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Commit 8f5b5f78 authored by Linus Torvalds's avatar Linus Torvalds
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Merge tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux 

Pull Rust updates from Miguel Ojeda:
 "The most notable change is the drop of the 'alloc' in-tree fork. This
  is nicely reflected in the diffstat as a ~10k lines drop. In turn,
  this makes the version upgrades way simpler and smaller in the future,
  e.g. the latest one in commit 56f64b37 ("rust: upgrade to Rust
  1.78.0").

  More importantly, this increases the chances that a newer compiler
  version just works, which in turn means supporting several compiler
  versions is easier now. Thus we will look into finally setting a
  minimum version in the near future.

  Toolchain and infrastructure:

   - Upgrade to Rust 1.78.0

     This time around, due to how the kernel and Rust schedules have
     aligned, there are two upgrades in fact. These allow us to remove
     one more unstable feature ('offset_of') from the list, among other
     improvements

   - Drop 'alloc' in-tree fork of the standard library crate, which
     means all the unstable features used by 'alloc' (~30 language ones,
     ~60 library ones) are not a concern anymore

   - Support DWARFv5 via the '-Zdwarf-version' flag

   - Support zlib and zstd debuginfo compression via the
     '-Zdebuginfo-compression' flag

  'kernel' crate:

   - Support allocation flags ('GFP_*'), particularly in 'Box' (via
     'BoxExt'), 'Vec' (via 'VecExt'), 'Arc' and 'UniqueArc', as well as
     in the 'init' module APIs

   - Remove usage of the 'allocator_api' unstable feature

   - Remove 'try_' prefix in allocation APIs' names

   - Add 'VecExt' (an extension trait) to be able to drop the 'alloc'
     fork

   - Add the '{make,to}_{upper,lower}case()' methods to 'CStr'/'CString'

   - Add the 'as_ptr' method to 'ThisModule'

   - Add the 'from_raw' method to 'ArcBorrow'

   - Add the 'into_unique_or_drop' method to 'Arc'

   - Display column number in the 'dbg!' macro output by applying the
     equivalent change done to the standard library one

   - Migrate 'Work' to '#[pin_data]' thanks to the changes in the
     'macros' crate, which allows to remove an unsafe call in its 'new'
     associated function

   - Prevent namespacing issues when using the '[try_][pin_]init!'
     macros by changing the generated name of guard variables

   - Make the 'get' method in 'Opaque' const

   - Implement the 'Default' trait for 'LockClassKey'

   - Remove unneeded 'kernel::prelude' imports from doctests

   - Remove redundant imports

  'macros' crate:

   - Add 'decl_generics' to 'parse_generics()' to support default
     values, and use that to allow them in '#[pin_data]'

  Helpers:

   - Trivial English grammar fix

  Documentation:

   - Add section on Rust Kselftests to the 'Testing' document

   - Expand the 'Abstractions vs. bindings' section of the 'General
     Information' document"

* tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux: (31 commits)
  rust: alloc: fix dangling pointer in VecExt<T>::reserve()
  rust: upgrade to Rust 1.78.0
  rust: kernel: remove redundant imports
  rust: sync: implement `Default` for `LockClassKey`
  docs: rust: extend abstraction and binding documentation
  docs: rust: Add instructions for the Rust kselftest
  rust: remove unneeded `kernel::prelude` imports from doctests
  rust: update `dbg!()` to format column number
  rust: helpers: Fix grammar in comment
  rust: init: change the generated name of guard variables
  rust: sync: add `Arc::into_unique_or_drop`
  rust: sync: add `ArcBorrow::from_raw`
  rust: types: Make Opaque::get const
  rust: kernel: remove usage of `allocator_api` unstable feature
  rust: init: update `init` module to take allocation flags
  rust: sync: update `Arc` and `UniqueArc` to take allocation flags
  rust: alloc: update `VecExt` to take allocation flags
  rust: alloc: introduce the `BoxExt` trait
  rust: alloc: introduce allocation flags
  rust: alloc: remove our fork of the `alloc` crate
  ...
parents 84c7d76b 97ab3e8e
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Showing with 878 additions and 10043 deletions
Documentation/process/changes.rst
View file @ 8f5b5f78
......@@ -31,7 +31,7 @@ you probably needn't concern yourself with pcmciautils.
====================== =============== ========================================
GNU C 5.1 gcc --version
Clang/LLVM (optional) 13.0.1 clang --version
Rust (optional) 1.76.0 rustc --version
Rust (optional) 1.78.0 rustc --version
bindgen (optional) 0.65.1 bindgen --version
GNU make 3.82 make --version
bash 4.2 bash --version
......
Documentation/rust/general-information.rst
View file @ 8f5b5f78
......@@ -64,6 +64,63 @@ but it is intended that coverage is expanded as time goes on. "Leaf" modules
(e.g. drivers) should not use the C bindings directly. Instead, subsystems
should provide as-safe-as-possible abstractions as needed.
.. code-block::
rust/bindings/
(rust/helpers.c)
include/ -----+ <-+
| |
drivers/ rust/kernel/ +----------+ <-+ |
fs/ | bindgen | |
.../ +-------------------+ +----------+ --+ |
| Abstractions | | |
+---------+ | +------+ +------+ | +----------+ | |
| my_foo | -----> | | foo | | bar | | -------> | Bindings | <-+ |
| driver | Safe | | sub- | | sub- | | Unsafe | | |
+---------+ | |system| |system| | | bindings | <-----+
| | +------+ +------+ | | crate | |
| | kernel crate | +----------+ |
| +-------------------+ |
| |
+------------------# FORBIDDEN #--------------------------------+
The main idea is to encapsulate all direct interaction with the kernel's C APIs
into carefully reviewed and documented abstractions. Then users of these
abstractions cannot introduce undefined behavior (UB) as long as:
#. The abstractions are correct ("sound").
#. Any ``unsafe`` blocks respect the safety contract necessary to call the
operations inside the block. Similarly, any ``unsafe impl``\ s respect the
safety contract necessary to implement the trait.
Bindings
~~~~~~~~
By including a C header from ``include/`` into
``rust/bindings/bindings_helper.h``, the ``bindgen`` tool will auto-generate the
bindings for the included subsystem. After building, see the ``*_generated.rs``
output files in the ``rust/bindings/`` directory.
For parts of the C header that ``bindgen`` does not auto generate, e.g. C
``inline`` functions or non-trivial macros, it is acceptable to add a small
wrapper function to ``rust/helpers.c`` to make it available for the Rust side as
well.
Abstractions
~~~~~~~~~~~~
Abstractions are the layer between the bindings and the in-kernel users. They
are located in ``rust/kernel/`` and their role is to encapsulate the unsafe
access to the bindings into an as-safe-as-possible API that they expose to their
users. Users of the abstractions include things like drivers or file systems
written in Rust.
Besides the safety aspect, the abstractions are supposed to be "ergonomic", in
the sense that they turn the C interfaces into "idiomatic" Rust code. Basic
examples are to turn the C resource acquisition and release into Rust
constructors and destructors or C integer error codes into Rust's ``Result``\ s.
Conditional compilation
-----------------------
......
Documentation/rust/testing.rst
View file @ 8f5b5f78
......@@ -6,10 +6,11 @@ Testing
This document contains useful information how to test the Rust code in the
kernel.
There are two sorts of tests:
There are three sorts of tests:
- The KUnit tests.
- The ``#[test]`` tests.
- The Kselftests.
The KUnit tests
---------------
......@@ -133,3 +134,25 @@ Additionally, there are the ``#[test]`` tests. These can be run using the
This requires the kernel ``.config`` and downloads external repositories. It
runs the ``#[test]`` tests on the host (currently) and thus is fairly limited in
what these tests can test.
The Kselftests
--------------
Kselftests are also available in the ``tools/testing/selftests/rust`` folder.
The kernel config options required for the tests are listed in the
``tools/testing/selftests/rust/config`` file and can be included with the aid
of the ``merge_config.sh`` script::
./scripts/kconfig/merge_config.sh .config tools/testing/selftests/rust/config
The kselftests are built within the kernel source tree and are intended to
be executed on a system that is running the same kernel.
Once a kernel matching the source tree has been installed and booted, the
tests can be compiled and executed using the following command::
make TARGETS="rust" kselftest
Refer to Documentation/dev-tools/kselftest.rst for the general Kselftest
documentation.
rust/Makefile
View file @ 8f5b5f78
......@@ -61,15 +61,9 @@ core-cfgs = \
--cfg no_fp_fmt_parse
alloc-cfgs = \
--cfg no_borrow \
--cfg no_fmt \
--cfg no_global_oom_handling \
--cfg no_macros \
--cfg no_rc \
--cfg no_str \
--cfg no_string \
--cfg no_sync \
--cfg no_thin
--cfg no_sync
quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
cmd_rustdoc = \
......@@ -123,7 +117,7 @@ rustdoc-compiler_builtins: $(src)/compiler_builtins.rs rustdoc-core FORCE
# due to things that are "configured out" vs. entirely non-existing ones.
rustdoc-alloc: private rustc_target_flags = $(alloc-cfgs) \
-Arustdoc::broken_intra_doc_links
rustdoc-alloc: $(src)/alloc/lib.rs rustdoc-core rustdoc-compiler_builtins FORCE
rustdoc-alloc: $(RUST_LIB_SRC)/alloc/src/lib.rs rustdoc-core rustdoc-compiler_builtins FORCE
+$(call if_changed,rustdoc)
rustdoc-kernel: private rustc_target_flags = --extern alloc \
......@@ -218,8 +212,6 @@ rusttest: rusttest-macros rusttest-kernel
# - `cargo` only considers the use case of building the standard library
# to use it in a given package. Thus we need to create a dummy package
# and pick the generated libraries from there.
# - Since we only keep a subset of upstream `alloc` in-tree, we need
# to recreate it on the fly by putting our sources on top.
# - The usual ways of modifying the dependency graph in `cargo` do not seem
# to apply for the `-Zbuild-std` steps, thus we have to mislead it
# by modifying the sources in the sysroot.
......@@ -238,8 +230,6 @@ quiet_cmd_rustsysroot = RUSTSYSROOT
rm -rf $(objtree)/$(obj)/test; \
mkdir -p $(objtree)/$(obj)/test; \
cp -a $(rustc_sysroot) $(objtree)/$(obj)/test/sysroot; \
cp -r $(srctree)/$(src)/alloc/* \
$(objtree)/$(obj)/test/sysroot/lib/rustlib/src/rust/library/alloc/src; \
echo '\#!/bin/sh' > $(objtree)/$(obj)/test/rustc_sysroot; \
echo "$(RUSTC) --sysroot=$(abspath $(objtree)/$(obj)/test/sysroot) \"\$$@\"" \
>> $(objtree)/$(obj)/test/rustc_sysroot; \
......@@ -447,7 +437,7 @@ $(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE
$(obj)/alloc.o: private skip_clippy = 1
$(obj)/alloc.o: private skip_flags = -Dunreachable_pub
$(obj)/alloc.o: private rustc_target_flags = $(alloc-cfgs)
$(obj)/alloc.o: $(src)/alloc/lib.rs $(obj)/compiler_builtins.o FORCE
$(obj)/alloc.o: $(RUST_LIB_SRC)/alloc/src/lib.rs $(obj)/compiler_builtins.o FORCE
+$(call if_changed_dep,rustc_library)
$(obj)/build_error.o: $(src)/build_error.rs $(obj)/compiler_builtins.o FORCE
......
rust/alloc/README.md deleted 100644 → 0
View file @ 84c7d76b
# `alloc`
These source files come from the Rust standard library, hosted in
the <https://github.com/rust-lang/rust> repository, licensed under
"Apache-2.0 OR MIT" and adapted for kernel use. For copyright details,
see <https://github.com/rust-lang/rust/blob/master/COPYRIGHT>.
Please note that these files should be kept as close as possible to
upstream. In general, only additions should be performed (e.g. new
methods). Eventually, changes should make it into upstream so that,
at some point, this fork can be dropped from the kernel tree.
The Rust upstream version on top of which these files are based matches
the output of `scripts/min-tool-version.sh rustc`.
## Rationale
On one hand, kernel folks wanted to keep `alloc` in-tree to have more
freedom in both workflow and actual features if actually needed
(e.g. receiver types if we ended up using them), which is reasonable.
On the other hand, Rust folks wanted to keep `alloc` as close as
upstream as possible and avoid as much divergence as possible, which
is also reasonable.
We agreed on a middle-ground: we would keep a subset of `alloc`
in-tree that would be as small and as close as possible to upstream.
Then, upstream can start adding the functions that we add to `alloc`
etc., until we reach a point where the kernel already knows exactly
what it needs in `alloc` and all the new methods are merged into
upstream, so that we can drop `alloc` from the kernel tree and go back
to using the upstream one.
By doing this, the kernel can go a bit faster now, and Rust can
slowly incorporate and discuss the changes as needed.
rust/alloc/alloc.rs deleted 100644 → 0
View file @ 84c7d76b
// SPDX-License-Identifier: Apache-2.0 OR MIT
//! Memory allocation APIs
#![stable(feature = "alloc_module", since = "1.28.0")]
#[cfg(not(test))]
use core::intrinsics;
#[cfg(not(test))]
use core::ptr::{self, NonNull};
#[stable(feature = "alloc_module", since = "1.28.0")]
#[doc(inline)]
pub use core::alloc::*;
#[cfg(test)]
mod tests;
extern "Rust" {
// These are the magic symbols to call the global allocator. rustc generates
// them to call `__rg_alloc` etc. if there is a `#[global_allocator]` attribute
// (the code expanding that attribute macro generates those functions), or to call
// the default implementations in std (`__rdl_alloc` etc. in `library/std/src/alloc.rs`)
// otherwise.
// The rustc fork of LLVM 14 and earlier also special-cases these function names to be able to optimize them
// like `malloc`, `realloc`, and `free`, respectively.
#[rustc_allocator]
#[rustc_nounwind]
fn __rust_alloc(size: usize, align: usize) -> *mut u8;
#[rustc_deallocator]
#[rustc_nounwind]
fn __rust_dealloc(ptr: *mut u8, size: usize, align: usize);
#[rustc_reallocator]
#[rustc_nounwind]
fn __rust_realloc(ptr: *mut u8, old_size: usize, align: usize, new_size: usize) -> *mut u8;
#[rustc_allocator_zeroed]
#[rustc_nounwind]
fn __rust_alloc_zeroed(size: usize, align: usize) -> *mut u8;
static __rust_no_alloc_shim_is_unstable: u8;
}
/// The global memory allocator.
///
/// This type implements the [`Allocator`] trait by forwarding calls
/// to the allocator registered with the `#[global_allocator]` attribute
/// if there is one, or the `std` crate’s default.
///
/// Note: while this type is unstable, the functionality it provides can be
/// accessed through the [free functions in `alloc`](self#functions).
#[unstable(feature = "allocator_api", issue = "32838")]
#[derive(Copy, Clone, Default, Debug)]
#[cfg(not(test))]
pub struct Global;
#[cfg(test)]
pub use std::alloc::Global;
/// Allocate memory with the global allocator.
///
/// This function forwards calls to the [`GlobalAlloc::alloc`] method
/// of the allocator registered with the `#[global_allocator]` attribute
/// if there is one, or the `std` crate’s default.
///
/// This function is expected to be deprecated in favor of the `alloc` method
/// of the [`Global`] type when it and the [`Allocator`] trait become stable.
///
/// # Safety
///
/// See [`GlobalAlloc::alloc`].
///
/// # Examples
///
/// ```
/// use std::alloc::{alloc, dealloc, handle_alloc_error, Layout};
///
/// unsafe {
/// let layout = Layout::new::<u16>();
/// let ptr = alloc(layout);
/// if ptr.is_null() {
/// handle_alloc_error(layout);
/// }
///
/// *(ptr as *mut u16) = 42;
/// assert_eq!(*(ptr as *mut u16), 42);
///
/// dealloc(ptr, layout);
/// }
/// ```
#[stable(feature = "global_alloc", since = "1.28.0")]
#[must_use = "losing the pointer will leak memory"]
#[inline]
pub unsafe fn alloc(layout: Layout) -> *mut u8 {
unsafe {
// Make sure we don't accidentally allow omitting the allocator shim in
// stable code until it is actually stabilized.
core::ptr::read_volatile(&__rust_no_alloc_shim_is_unstable);
__rust_alloc(layout.size(), layout.align())
}
}
/// Deallocate memory with the global allocator.
///
/// This function forwards calls to the [`GlobalAlloc::dealloc`] method
/// of the allocator registered with the `#[global_allocator]` attribute
/// if there is one, or the `std` crate’s default.
///
/// This function is expected to be deprecated in favor of the `dealloc` method
/// of the [`Global`] type when it and the [`Allocator`] trait become stable.
///
/// # Safety
///
/// See [`GlobalAlloc::dealloc`].
#[stable(feature = "global_alloc", since = "1.28.0")]
#[inline]
pub unsafe fn dealloc(ptr: *mut u8, layout: Layout) {
unsafe { __rust_dealloc(ptr, layout.size(), layout.align()) }
}
/// Reallocate memory with the global allocator.
///
/// This function forwards calls to the [`GlobalAlloc::realloc`] method
/// of the allocator registered with the `#[global_allocator]` attribute
/// if there is one, or the `std` crate’s default.
///
/// This function is expected to be deprecated in favor of the `realloc` method
/// of the [`Global`] type when it and the [`Allocator`] trait become stable.
///
/// # Safety
///
/// See [`GlobalAlloc::realloc`].
#[stable(feature = "global_alloc", since = "1.28.0")]
#[must_use = "losing the pointer will leak memory"]
#[inline]
pub unsafe fn realloc(ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
unsafe { __rust_realloc(ptr, layout.size(), layout.align(), new_size) }
}
/// Allocate zero-initialized memory with the global allocator.
///
/// This function forwards calls to the [`GlobalAlloc::alloc_zeroed`] method
/// of the allocator registered with the `#[global_allocator]` attribute
/// if there is one, or the `std` crate’s default.
///
/// This function is expected to be deprecated in favor of the `alloc_zeroed` method
/// of the [`Global`] type when it and the [`Allocator`] trait become stable.
///
/// # Safety
///
/// See [`GlobalAlloc::alloc_zeroed`].
///
/// # Examples
///
/// ```
/// use std::alloc::{alloc_zeroed, dealloc, Layout};
///
/// unsafe {
/// let layout = Layout::new::<u16>();
/// let ptr = alloc_zeroed(layout);
///
/// assert_eq!(*(ptr as *mut u16), 0);
///
/// dealloc(ptr, layout);
/// }
/// ```
#[stable(feature = "global_alloc", since = "1.28.0")]
#[must_use = "losing the pointer will leak memory"]
#[inline]
pub unsafe fn alloc_zeroed(layout: Layout) -> *mut u8 {
unsafe { __rust_alloc_zeroed(layout.size(), layout.align()) }
}
#[cfg(not(test))]
impl Global {
#[inline]
fn alloc_impl(&self, layout: Layout, zeroed: bool) -> Result<NonNull<[u8]>, AllocError> {
match layout.size() {
0 => Ok(NonNull::slice_from_raw_parts(layout.dangling(), 0)),
// SAFETY: `layout` is non-zero in size,
size => unsafe {
let raw_ptr = if zeroed { alloc_zeroed(layout) } else { alloc(layout) };
let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;
Ok(NonNull::slice_from_raw_parts(ptr, size))
},
}
}
// SAFETY: Same as `Allocator::grow`
#[inline]
unsafe fn grow_impl(
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
zeroed: bool,
) -> Result<NonNull<[u8]>, AllocError> {
debug_assert!(
new_layout.size() >= old_layout.size(),
"`new_layout.size()` must be greater than or equal to `old_layout.size()`"
);
match old_layout.size() {
0 => self.alloc_impl(new_layout, zeroed),
// SAFETY: `new_size` is non-zero as `old_size` is greater than or equal to `new_size`
// as required by safety conditions. Other conditions must be upheld by the caller
old_size if old_layout.align() == new_layout.align() => unsafe {
let new_size = new_layout.size();
// `realloc` probably checks for `new_size >= old_layout.size()` or something similar.
intrinsics::assume(new_size >= old_layout.size());
let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size);
let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;
if zeroed {
raw_ptr.add(old_size).write_bytes(0, new_size - old_size);
}
Ok(NonNull::slice_from_raw_parts(ptr, new_size))
},
// SAFETY: because `new_layout.size()` must be greater than or equal to `old_size`,
// both the old and new memory allocation are valid for reads and writes for `old_size`
// bytes. Also, because the old allocation wasn't yet deallocated, it cannot overlap
// `new_ptr`. Thus, the call to `copy_nonoverlapping` is safe. The safety contract
// for `dealloc` must be upheld by the caller.
old_size => unsafe {
let new_ptr = self.alloc_impl(new_layout, zeroed)?;
ptr::copy_nonoverlapping(ptr.as_ptr(), new_ptr.as_mut_ptr(), old_size);
self.deallocate(ptr, old_layout);
Ok(new_ptr)
},
}
}
}
#[unstable(feature = "allocator_api", issue = "32838")]
#[cfg(not(test))]
unsafe impl Allocator for Global {
#[inline]
fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
self.alloc_impl(layout, false)
}
#[inline]
fn allocate_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
self.alloc_impl(layout, true)
}
#[inline]
unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
if layout.size() != 0 {
// SAFETY: `layout` is non-zero in size,
// other conditions must be upheld by the caller
unsafe { dealloc(ptr.as_ptr(), layout) }
}
}
#[inline]
unsafe fn grow(
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
) -> Result<NonNull<[u8]>, AllocError> {
// SAFETY: all conditions must be upheld by the caller
unsafe { self.grow_impl(ptr, old_layout, new_layout, false) }
}
#[inline]
unsafe fn grow_zeroed(
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
) -> Result<NonNull<[u8]>, AllocError> {
// SAFETY: all conditions must be upheld by the caller
unsafe { self.grow_impl(ptr, old_layout, new_layout, true) }
}
#[inline]
unsafe fn shrink(
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
) -> Result<NonNull<[u8]>, AllocError> {
debug_assert!(
new_layout.size() <= old_layout.size(),
"`new_layout.size()` must be smaller than or equal to `old_layout.size()`"
);
match new_layout.size() {
// SAFETY: conditions must be upheld by the caller
0 => unsafe {
self.deallocate(ptr, old_layout);
Ok(NonNull::slice_from_raw_parts(new_layout.dangling(), 0))
},
// SAFETY: `new_size` is non-zero. Other conditions must be upheld by the caller
new_size if old_layout.align() == new_layout.align() => unsafe {
// `realloc` probably checks for `new_size <= old_layout.size()` or something similar.
intrinsics::assume(new_size <= old_layout.size());
let raw_ptr = realloc(ptr.as_ptr(), old_layout, new_size);
let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;
Ok(NonNull::slice_from_raw_parts(ptr, new_size))
},
// SAFETY: because `new_size` must be smaller than or equal to `old_layout.size()`,
// both the old and new memory allocation are valid for reads and writes for `new_size`
// bytes. Also, because the old allocation wasn't yet deallocated, it cannot overlap
// `new_ptr`. Thus, the call to `copy_nonoverlapping` is safe. The safety contract
// for `dealloc` must be upheld by the caller.
new_size => unsafe {
let new_ptr = self.allocate(new_layout)?;
ptr::copy_nonoverlapping(ptr.as_ptr(), new_ptr.as_mut_ptr(), new_size);
self.deallocate(ptr, old_layout);
Ok(new_ptr)
},
}
}
}
/// The allocator for unique pointers.
#[cfg(all(not(no_global_oom_handling), not(test)))]
#[lang = "exchange_malloc"]
#[inline]
unsafe fn exchange_malloc(size: usize, align: usize) -> *mut u8 {
let layout = unsafe { Layout::from_size_align_unchecked(size, align) };
match Global.allocate(layout) {
Ok(ptr) => ptr.as_mut_ptr(),
Err(_) => handle_alloc_error(layout),
}
}
// # Allocation error handler
#[cfg(not(no_global_oom_handling))]
extern "Rust" {
// This is the magic symbol to call the global alloc error handler. rustc generates
// it to call `__rg_oom` if there is a `#[alloc_error_handler]`, or to call the
// default implementations below (`__rdl_oom`) otherwise.
fn __rust_alloc_error_handler(size: usize, align: usize) -> !;
}
/// Signal a memory allocation error.
///
/// Callers of memory allocation APIs wishing to cease execution
/// in response to an allocation error are encouraged to call this function,
/// rather than directly invoking [`panic!`] or similar.
///
/// This function is guaranteed to diverge (not return normally with a value), but depending on
/// global configuration, it may either panic (resulting in unwinding or aborting as per
/// configuration for all panics), or abort the process (with no unwinding).
///
/// The default behavior is:
///
/// * If the binary links against `std` (typically the case), then
/// print a message to standard error and abort the process.
/// This behavior can be replaced with [`set_alloc_error_hook`] and [`take_alloc_error_hook`].
/// Future versions of Rust may panic by default instead.
///
/// * If the binary does not link against `std` (all of its crates are marked
/// [`#![no_std]`][no_std]), then call [`panic!`] with a message.
/// [The panic handler] applies as to any panic.
///
/// [`set_alloc_error_hook`]: ../../std/alloc/fn.set_alloc_error_hook.html
/// [`take_alloc_error_hook`]: ../../std/alloc/fn.take_alloc_error_hook.html
/// [The panic handler]: https://doc.rust-lang.org/reference/runtime.html#the-panic_handler-attribute
/// [no_std]: https://doc.rust-lang.org/reference/names/preludes.html#the-no_std-attribute
#[stable(feature = "global_alloc", since = "1.28.0")]
#[rustc_const_unstable(feature = "const_alloc_error", issue = "92523")]
#[cfg(all(not(no_global_oom_handling), not(test)))]
#[cold]
pub const fn handle_alloc_error(layout: Layout) -> ! {
const fn ct_error(_: Layout) -> ! {
panic!("allocation failed");
}
#[inline]
fn rt_error(layout: Layout) -> ! {
unsafe {
__rust_alloc_error_handler(layout.size(), layout.align());
}
}
#[cfg(not(feature = "panic_immediate_abort"))]
unsafe {
core::intrinsics::const_eval_select((layout,), ct_error, rt_error)
}
#[cfg(feature = "panic_immediate_abort")]
ct_error(layout)
}
// For alloc test `std::alloc::handle_alloc_error` can be used directly.
#[cfg(all(not(no_global_oom_handling), test))]
pub use std::alloc::handle_alloc_error;
#[cfg(all(not(no_global_oom_handling), not(test)))]
#[doc(hidden)]
#[allow(unused_attributes)]
#[unstable(feature = "alloc_internals", issue = "none")]
pub mod __alloc_error_handler {
// called via generated `__rust_alloc_error_handler` if there is no
// `#[alloc_error_handler]`.
#[rustc_std_internal_symbol]
pub unsafe fn __rdl_oom(size: usize, _align: usize) -> ! {
extern "Rust" {
// This symbol is emitted by rustc next to __rust_alloc_error_handler.
// Its value depends on the -Zoom={panic,abort} compiler option.
static __rust_alloc_error_handler_should_panic: u8;
}
if unsafe { __rust_alloc_error_handler_should_panic != 0 } {
panic!("memory allocation of {size} bytes failed")
} else {
core::panicking::panic_nounwind_fmt(
format_args!("memory allocation of {size} bytes failed"),
/* force_no_backtrace */ false,
)
}
}
}
#[cfg(not(no_global_oom_handling))]
/// Specialize clones into pre-allocated, uninitialized memory.
/// Used by `Box::clone` and `Rc`/`Arc::make_mut`.
pub(crate) trait WriteCloneIntoRaw: Sized {
unsafe fn write_clone_into_raw(&self, target: *mut Self);
}
#[cfg(not(no_global_oom_handling))]
impl<T: Clone> WriteCloneIntoRaw for T {
#[inline]
default unsafe fn write_clone_into_raw(&self, target: *mut Self) {
// Having allocated *first* may allow the optimizer to create
// the cloned value in-place, skipping the local and move.
unsafe { target.write(self.clone()) };
}
}
#[cfg(not(no_global_oom_handling))]
impl<T: Copy> WriteCloneIntoRaw for T {
#[inline]
unsafe fn write_clone_into_raw(&self, target: *mut Self) {
// We can always copy in-place, without ever involving a local value.
unsafe { target.copy_from_nonoverlapping(self, 1) };
}
}
rust/alloc/boxed.rs deleted 100644 → 0
View file @ 84c7d76b
// SPDX-License-Identifier: Apache-2.0 OR MIT
//! The `Box<T>` type for heap allocation.
//!
//! [`Box<T>`], casually referred to as a 'box', provides the simplest form of
//! heap allocation in Rust. Boxes provide ownership for this allocation, and
//! drop their contents when they go out of scope. Boxes also ensure that they
//! never allocate more than `isize::MAX` bytes.
//!
//! # Examples
//!
//! Move a value from the stack to the heap by creating a [`Box`]:
//!
//! ```
//! let val: u8 = 5;
//! let boxed: Box<u8> = Box::new(val);
//! ```
//!
//! Move a value from a [`Box`] back to the stack by [dereferencing]:
//!
//! ```
//! let boxed: Box<u8> = Box::new(5);
//! let val: u8 = *boxed;
//! ```
//!
//! Creating a recursive data structure:
//!
//! ```
//! #[derive(Debug)]
//! enum List<T> {
//! Cons(T, Box<List<T>>),
//! Nil,
//! }
//!
//! let list: List<i32> = List::Cons(1, Box::new(List::Cons(2, Box::new(List::Nil))));
//! println!("{list:?}");
//! ```
//!
//! This will print `Cons(1, Cons(2, Nil))`.
//!
//! Recursive structures must be boxed, because if the definition of `Cons`
//! looked like this:
//!
//! ```compile_fail,E0072
//! # enum List<T> {
//! Cons(T, List<T>),
//! # }
//! ```
//!
//! It wouldn't work. This is because the size of a `List` depends on how many
//! elements are in the list, and so we don't know how much memory to allocate
//! for a `Cons`. By introducing a [`Box<T>`], which has a defined size, we know how
//! big `Cons` needs to be.
//!
//! # Memory layout
//!
//! For non-zero-sized values, a [`Box`] will use the [`Global`] allocator for
//! its allocation. It is valid to convert both ways between a [`Box`] and a
//! raw pointer allocated with the [`Global`] allocator, given that the
//! [`Layout`] used with the allocator is correct for the type. More precisely,
//! a `value: *mut T` that has been allocated with the [`Global`] allocator
//! with `Layout::for_value(&*value)` may be converted into a box using
//! [`Box::<T>::from_raw(value)`]. Conversely, the memory backing a `value: *mut
//! T` obtained from [`Box::<T>::into_raw`] may be deallocated using the
//! [`Global`] allocator with [`Layout::for_value(&*value)`].
//!
//! For zero-sized values, the `Box` pointer still has to be [valid] for reads
//! and writes and sufficiently aligned. In particular, casting any aligned
//! non-zero integer literal to a raw pointer produces a valid pointer, but a
//! pointer pointing into previously allocated memory that since got freed is
//! not valid. The recommended way to build a Box to a ZST if `Box::new` cannot
//! be used is to use [`ptr::NonNull::dangling`].
//!
//! So long as `T: Sized`, a `Box<T>` is guaranteed to be represented
//! as a single pointer and is also ABI-compatible with C pointers
//! (i.e. the C type `T*`). This means that if you have extern "C"
//! Rust functions that will be called from C, you can define those
//! Rust functions using `Box<T>` types, and use `T*` as corresponding
//! type on the C side. As an example, consider this C header which
//! declares functions that create and destroy some kind of `Foo`
//! value:
//!
//! ```c
//! /* C header */
//!
//! /* Returns ownership to the caller */
//! struct Foo* foo_new(void);
//!
//! /* Takes ownership from the caller; no-op when invoked with null */
//! void foo_delete(struct Foo*);
//! ```
//!
//! These two functions might be implemented in Rust as follows. Here, the
//! `struct Foo*` type from C is translated to `Box<Foo>`, which captures
//! the ownership constraints. Note also that the nullable argument to
//! `foo_delete` is represented in Rust as `Option<Box<Foo>>`, since `Box<Foo>`
//! cannot be null.
//!
//! ```
//! #[repr(C)]
//! pub struct Foo;
//!
//! #[no_mangle]
//! pub extern "C" fn foo_new() -> Box<Foo> {
//! Box::new(Foo)
//! }
//!
//! #[no_mangle]
//! pub extern "C" fn foo_delete(_: Option<Box<Foo>>) {}
//! ```
//!
//! Even though `Box<T>` has the same representation and C ABI as a C pointer,
//! this does not mean that you can convert an arbitrary `T*` into a `Box<T>`
//! and expect things to work. `Box<T>` values will always be fully aligned,
//! non-null pointers. Moreover, the destructor for `Box<T>` will attempt to
//! free the value with the global allocator. In general, the best practice
//! is to only use `Box<T>` for pointers that originated from the global
//! allocator.
//!
//! **Important.** At least at present, you should avoid using
//! `Box<T>` types for functions that are defined in C but invoked
//! from Rust. In those cases, you should directly mirror the C types
//! as closely as possible. Using types like `Box<T>` where the C
//! definition is just using `T*` can lead to undefined behavior, as
//! described in [rust-lang/unsafe-code-guidelines#198][ucg#198].
//!
//! # Considerations for unsafe code
//!
//! **Warning: This section is not normative and is subject to change, possibly
//! being relaxed in the future! It is a simplified summary of the rules
//! currently implemented in the compiler.**
//!
//! The aliasing rules for `Box<T>` are the same as for `&mut T`. `Box<T>`
//! asserts uniqueness over its content. Using raw pointers derived from a box
//! after that box has been mutated through, moved or borrowed as `&mut T`
//! is not allowed. For more guidance on working with box from unsafe code, see
//! [rust-lang/unsafe-code-guidelines#326][ucg#326].
//!
//!
//! [ucg#198]: https://github.com/rust-lang/unsafe-code-guidelines/issues/198
//! [ucg#326]: https://github.com/rust-lang/unsafe-code-guidelines/issues/326
//! [dereferencing]: core::ops::Deref
//! [`Box::<T>::from_raw(value)`]: Box::from_raw
//! [`Global`]: crate::alloc::Global
//! [`Layout`]: crate::alloc::Layout
//! [`Layout::for_value(&*value)`]: crate::alloc::Layout::for_value
//! [valid]: ptr#safety
#![stable(feature = "rust1", since = "1.0.0")]
use core::any::Any;
use core::async_iter::AsyncIterator;
use core::borrow;
use core::cmp::Ordering;
use core::error::Error;
use core::fmt;
use core::future::Future;
use core::hash::{Hash, Hasher};
use core::iter::FusedIterator;
use core::marker::Tuple;
use core::marker::Unsize;
use core::mem::{self, SizedTypeProperties};
use core::ops::{
CoerceUnsized, Coroutine, CoroutineState, Deref, DerefMut, DispatchFromDyn, Receiver,
};
use core::pin::Pin;
use core::ptr::{self, NonNull, Unique};
use core::task::{Context, Poll};
#[cfg(not(no_global_oom_handling))]
use crate::alloc::{handle_alloc_error, WriteCloneIntoRaw};
use crate::alloc::{AllocError, Allocator, Global, Layout};
#[cfg(not(no_global_oom_handling))]
use crate::borrow::Cow;
use crate::raw_vec::RawVec;
#[cfg(not(no_global_oom_handling))]
use crate::str::from_boxed_utf8_unchecked;
#[cfg(not(no_global_oom_handling))]
use crate::string::String;
#[cfg(not(no_global_oom_handling))]
use crate::vec::Vec;
#[cfg(not(no_thin))]
#[unstable(feature = "thin_box", issue = "92791")]
pub use thin::ThinBox;
#[cfg(not(no_thin))]
mod thin;
/// A pointer type that uniquely owns a heap allocation of type `T`.
///
/// See the [module-level documentation](../../std/boxed/index.html) for more.
#[lang = "owned_box"]
#[fundamental]
#[stable(feature = "rust1", since = "1.0.0")]
// The declaration of the `Box` struct must be kept in sync with the
// `alloc::alloc::box_free` function or ICEs will happen. See the comment
// on `box_free` for more details.
pub struct Box<
T: ?Sized,
#[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global,
>(Unique<T>, A);
impl<T> Box<T> {
/// Allocates memory on the heap and then places `x` into it.
///
/// This doesn't actually allocate if `T` is zero-sized.
///
/// # Examples
///
/// ```
/// let five = Box::new(5);
/// ```
#[cfg(not(no_global_oom_handling))]
#[inline(always)]
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[rustc_diagnostic_item = "box_new"]
pub fn new(x: T) -> Self {
#[rustc_box]
Box::new(x)
}
/// Constructs a new box with uninitialized contents.
///
/// # Examples
///
/// ```
/// #![feature(new_uninit)]
///
/// let mut five = Box::<u32>::new_uninit();
///
/// let five = unsafe {
/// // Deferred initialization:
/// five.as_mut_ptr().write(5);
///
/// five.assume_init()
/// };
///
/// assert_eq!(*five, 5)
/// ```
#[cfg(not(no_global_oom_handling))]
#[unstable(feature = "new_uninit", issue = "63291")]
#[must_use]
#[inline]
pub fn new_uninit() -> Box<mem::MaybeUninit<T>> {
Self::new_uninit_in(Global)
}
/// Constructs a new `Box` with uninitialized contents, with the memory
/// being filled with `0` bytes.
///
/// See [`MaybeUninit::zeroed`][zeroed] for examples of correct and incorrect usage
/// of this method.
///
/// # Examples
///
/// ```
/// #![feature(new_uninit)]
///
/// let zero = Box::<u32>::new_zeroed();
/// let zero = unsafe { zero.assume_init() };
///
/// assert_eq!(*zero, 0)
/// ```
///
/// [zeroed]: mem::MaybeUninit::zeroed
#[cfg(not(no_global_oom_handling))]
#[inline]
#[unstable(feature = "new_uninit", issue = "63291")]
#[must_use]
pub fn new_zeroed() -> Box<mem::MaybeUninit<T>> {
Self::new_zeroed_in(Global)
}
/// Constructs a new `Pin<Box<T>>`. If `T` does not implement [`Unpin`], then
/// `x` will be pinned in memory and unable to be moved.
///
/// Constructing and pinning of the `Box` can also be done in two steps: `Box::pin(x)`
/// does the same as <code>[Box::into_pin]\([Box::new]\(x))</code>. Consider using
/// [`into_pin`](Box::into_pin) if you already have a `Box<T>`, or if you want to
/// construct a (pinned) `Box` in a different way than with [`Box::new`].
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "pin", since = "1.33.0")]
#[must_use]
#[inline(always)]
pub fn pin(x: T) -> Pin<Box<T>> {
Box::new(x).into()
}
/// Allocates memory on the heap then places `x` into it,
/// returning an error if the allocation fails
///
/// This doesn't actually allocate if `T` is zero-sized.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api)]
///
/// let five = Box::try_new(5)?;
/// # Ok::<(), std::alloc::AllocError>(())
/// ```
#[unstable(feature = "allocator_api", issue = "32838")]
#[inline]
pub fn try_new(x: T) -> Result<Self, AllocError> {
Self::try_new_in(x, Global)
}
/// Constructs a new box with uninitialized contents on the heap,
/// returning an error if the allocation fails
///
/// # Examples
///
/// ```
/// #![feature(allocator_api, new_uninit)]
///
/// let mut five = Box::<u32>::try_new_uninit()?;
///
/// let five = unsafe {
/// // Deferred initialization:
/// five.as_mut_ptr().write(5);
///
/// five.assume_init()
/// };
///
/// assert_eq!(*five, 5);
/// # Ok::<(), std::alloc::AllocError>(())
/// ```
#[unstable(feature = "allocator_api", issue = "32838")]
// #[unstable(feature = "new_uninit", issue = "63291")]
#[inline]
pub fn try_new_uninit() -> Result<Box<mem::MaybeUninit<T>>, AllocError> {
Box::try_new_uninit_in(Global)
}
/// Constructs a new `Box` with uninitialized contents, with the memory
/// being filled with `0` bytes on the heap
///
/// See [`MaybeUninit::zeroed`][zeroed] for examples of correct and incorrect usage
/// of this method.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api, new_uninit)]
///
/// let zero = Box::<u32>::try_new_zeroed()?;
/// let zero = unsafe { zero.assume_init() };
///
/// assert_eq!(*zero, 0);
/// # Ok::<(), std::alloc::AllocError>(())
/// ```
///
/// [zeroed]: mem::MaybeUninit::zeroed
#[unstable(feature = "allocator_api", issue = "32838")]
// #[unstable(feature = "new_uninit", issue = "63291")]
#[inline]
pub fn try_new_zeroed() -> Result<Box<mem::MaybeUninit<T>>, AllocError> {
Box::try_new_zeroed_in(Global)
}
}
impl<T, A: Allocator> Box<T, A> {
/// Allocates memory in the given allocator then places `x` into it.
///
/// This doesn't actually allocate if `T` is zero-sized.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api)]
///
/// use std::alloc::System;
///
/// let five = Box::new_in(5, System);
/// ```
#[cfg(not(no_global_oom_handling))]
#[unstable(feature = "allocator_api", issue = "32838")]
#[must_use]
#[inline]
pub fn new_in(x: T, alloc: A) -> Self
where
A: Allocator,
{
let mut boxed = Self::new_uninit_in(alloc);
unsafe {
boxed.as_mut_ptr().write(x);
boxed.assume_init()
}
}
/// Allocates memory in the given allocator then places `x` into it,
/// returning an error if the allocation fails
///
/// This doesn't actually allocate if `T` is zero-sized.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api)]
///
/// use std::alloc::System;
///
/// let five = Box::try_new_in(5, System)?;
/// # Ok::<(), std::alloc::AllocError>(())
/// ```
#[unstable(feature = "allocator_api", issue = "32838")]
#[inline]
pub fn try_new_in(x: T, alloc: A) -> Result<Self, AllocError>
where
A: Allocator,
{
let mut boxed = Self::try_new_uninit_in(alloc)?;
unsafe {
boxed.as_mut_ptr().write(x);
Ok(boxed.assume_init())
}
}
/// Constructs a new box with uninitialized contents in the provided allocator.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api, new_uninit)]
///
/// use std::alloc::System;
///
/// let mut five = Box::<u32, _>::new_uninit_in(System);
///
/// let five = unsafe {
/// // Deferred initialization:
/// five.as_mut_ptr().write(5);
///
/// five.assume_init()
/// };
///
/// assert_eq!(*five, 5)
/// ```
#[unstable(feature = "allocator_api", issue = "32838")]
#[cfg(not(no_global_oom_handling))]
#[must_use]
// #[unstable(feature = "new_uninit", issue = "63291")]
pub fn new_uninit_in(alloc: A) -> Box<mem::MaybeUninit<T>, A>
where
A: Allocator,
{
let layout = Layout::new::<mem::MaybeUninit<T>>();
// NOTE: Prefer match over unwrap_or_else since closure sometimes not inlineable.
// That would make code size bigger.
match Box::try_new_uninit_in(alloc) {
Ok(m) => m,
Err(_) => handle_alloc_error(layout),
}
}
/// Constructs a new box with uninitialized contents in the provided allocator,
/// returning an error if the allocation fails
///
/// # Examples
///
/// ```
/// #![feature(allocator_api, new_uninit)]
///
/// use std::alloc::System;
///
/// let mut five = Box::<u32, _>::try_new_uninit_in(System)?;
///
/// let five = unsafe {
/// // Deferred initialization:
/// five.as_mut_ptr().write(5);
///
/// five.assume_init()
/// };
///
/// assert_eq!(*five, 5);
/// # Ok::<(), std::alloc::AllocError>(())
/// ```
#[unstable(feature = "allocator_api", issue = "32838")]
// #[unstable(feature = "new_uninit", issue = "63291")]
pub fn try_new_uninit_in(alloc: A) -> Result<Box<mem::MaybeUninit<T>, A>, AllocError>
where
A: Allocator,
{
let ptr = if T::IS_ZST {
NonNull::dangling()
} else {
let layout = Layout::new::<mem::MaybeUninit<T>>();
alloc.allocate(layout)?.cast()
};
unsafe { Ok(Box::from_raw_in(ptr.as_ptr(), alloc)) }
}
/// Constructs a new `Box` with uninitialized contents, with the memory
/// being filled with `0` bytes in the provided allocator.
///
/// See [`MaybeUninit::zeroed`][zeroed] for examples of correct and incorrect usage
/// of this method.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api, new_uninit)]
///
/// use std::alloc::System;
///
/// let zero = Box::<u32, _>::new_zeroed_in(System);
/// let zero = unsafe { zero.assume_init() };
///
/// assert_eq!(*zero, 0)
/// ```
///
/// [zeroed]: mem::MaybeUninit::zeroed
#[unstable(feature = "allocator_api", issue = "32838")]
#[cfg(not(no_global_oom_handling))]
// #[unstable(feature = "new_uninit", issue = "63291")]
#[must_use]
pub fn new_zeroed_in(alloc: A) -> Box<mem::MaybeUninit<T>, A>
where
A: Allocator,
{
let layout = Layout::new::<mem::MaybeUninit<T>>();
// NOTE: Prefer match over unwrap_or_else since closure sometimes not inlineable.
// That would make code size bigger.
match Box::try_new_zeroed_in(alloc) {
Ok(m) => m,
Err(_) => handle_alloc_error(layout),
}
}
/// Constructs a new `Box` with uninitialized contents, with the memory
/// being filled with `0` bytes in the provided allocator,
/// returning an error if the allocation fails,
///
/// See [`MaybeUninit::zeroed`][zeroed] for examples of correct and incorrect usage
/// of this method.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api, new_uninit)]
///
/// use std::alloc::System;
///
/// let zero = Box::<u32, _>::try_new_zeroed_in(System)?;
/// let zero = unsafe { zero.assume_init() };
///
/// assert_eq!(*zero, 0);
/// # Ok::<(), std::alloc::AllocError>(())
/// ```
///
/// [zeroed]: mem::MaybeUninit::zeroed
#[unstable(feature = "allocator_api", issue = "32838")]
// #[unstable(feature = "new_uninit", issue = "63291")]
pub fn try_new_zeroed_in(alloc: A) -> Result<Box<mem::MaybeUninit<T>, A>, AllocError>
where
A: Allocator,
{
let ptr = if T::IS_ZST {
NonNull::dangling()
} else {
let layout = Layout::new::<mem::MaybeUninit<T>>();
alloc.allocate_zeroed(layout)?.cast()
};
unsafe { Ok(Box::from_raw_in(ptr.as_ptr(), alloc)) }
}
/// Constructs a new `Pin<Box<T, A>>`. If `T` does not implement [`Unpin`], then
/// `x` will be pinned in memory and unable to be moved.
///
/// Constructing and pinning of the `Box` can also be done in two steps: `Box::pin_in(x, alloc)`
/// does the same as <code>[Box::into_pin]\([Box::new_in]\(x, alloc))</code>. Consider using
/// [`into_pin`](Box::into_pin) if you already have a `Box<T, A>`, or if you want to
/// construct a (pinned) `Box` in a different way than with [`Box::new_in`].
#[cfg(not(no_global_oom_handling))]
#[unstable(feature = "allocator_api", issue = "32838")]
#[must_use]
#[inline(always)]
pub fn pin_in(x: T, alloc: A) -> Pin<Self>
where
A: 'static + Allocator,
{
Self::into_pin(Self::new_in(x, alloc))
}
/// Converts a `Box<T>` into a `Box<[T]>`
///
/// This conversion does not allocate on the heap and happens in place.
#[unstable(feature = "box_into_boxed_slice", issue = "71582")]
pub fn into_boxed_slice(boxed: Self) -> Box<[T], A> {
let (raw, alloc) = Box::into_raw_with_allocator(boxed);
unsafe { Box::from_raw_in(raw as *mut [T; 1], alloc) }
}
/// Consumes the `Box`, returning the wrapped value.
///
/// # Examples
///
/// ```
/// #![feature(box_into_inner)]
///
/// let c = Box::new(5);
///
/// assert_eq!(Box::into_inner(c), 5);
/// ```
#[unstable(feature = "box_into_inner", issue = "80437")]
#[inline]
pub fn into_inner(boxed: Self) -> T {
*boxed
}
}
impl<T> Box<[T]> {
/// Constructs a new boxed slice with uninitialized contents.
///
/// # Examples
///
/// ```
/// #![feature(new_uninit)]
///
/// let mut values = Box::<[u32]>::new_uninit_slice(3);
///
/// let values = unsafe {
/// // Deferred initialization:
/// values[0].as_mut_ptr().write(1);
/// values[1].as_mut_ptr().write(2);
/// values[2].as_mut_ptr().write(3);
///
/// values.assume_init()
/// };
///
/// assert_eq!(*values, [1, 2, 3])
/// ```
#[cfg(not(no_global_oom_handling))]
#[unstable(feature = "new_uninit", issue = "63291")]
#[must_use]
pub fn new_uninit_slice(len: usize) -> Box<[mem::MaybeUninit<T>]> {
unsafe { RawVec::with_capacity(len).into_box(len) }
}
/// Constructs a new boxed slice with uninitialized contents, with the memory
/// being filled with `0` bytes.
///
/// See [`MaybeUninit::zeroed`][zeroed] for examples of correct and incorrect usage
/// of this method.
///
/// # Examples
///
/// ```
/// #![feature(new_uninit)]
///
/// let values = Box::<[u32]>::new_zeroed_slice(3);
/// let values = unsafe { values.assume_init() };
///
/// assert_eq!(*values, [0, 0, 0])
/// ```
///
/// [zeroed]: mem::MaybeUninit::zeroed
#[cfg(not(no_global_oom_handling))]
#[unstable(feature = "new_uninit", issue = "63291")]
#[must_use]
pub fn new_zeroed_slice(len: usize) -> Box<[mem::MaybeUninit<T>]> {
unsafe { RawVec::with_capacity_zeroed(len).into_box(len) }
}
/// Constructs a new boxed slice with uninitialized contents. Returns an error if
/// the allocation fails
///
/// # Examples
///
/// ```
/// #![feature(allocator_api, new_uninit)]
///
/// let mut values = Box::<[u32]>::try_new_uninit_slice(3)?;
/// let values = unsafe {
/// // Deferred initialization:
/// values[0].as_mut_ptr().write(1);
/// values[1].as_mut_ptr().write(2);
/// values[2].as_mut_ptr().write(3);
/// values.assume_init()
/// };
///
/// assert_eq!(*values, [1, 2, 3]);
/// # Ok::<(), std::alloc::AllocError>(())
/// ```
#[unstable(feature = "allocator_api", issue = "32838")]
#[inline]
pub fn try_new_uninit_slice(len: usize) -> Result<Box<[mem::MaybeUninit<T>]>, AllocError> {
let ptr = if T::IS_ZST || len == 0 {
NonNull::dangling()
} else {
let layout = match Layout::array::<mem::MaybeUninit<T>>(len) {
Ok(l) => l,
Err(_) => return Err(AllocError),
};
Global.allocate(layout)?.cast()
};
unsafe { Ok(RawVec::from_raw_parts_in(ptr.as_ptr(), len, Global).into_box(len)) }
}
/// Constructs a new boxed slice with uninitialized contents, with the memory
/// being filled with `0` bytes. Returns an error if the allocation fails
///
/// See [`MaybeUninit::zeroed`][zeroed] for examples of correct and incorrect usage
/// of this method.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api, new_uninit)]
///
/// let values = Box::<[u32]>::try_new_zeroed_slice(3)?;
/// let values = unsafe { values.assume_init() };
///
/// assert_eq!(*values, [0, 0, 0]);
/// # Ok::<(), std::alloc::AllocError>(())
/// ```
///
/// [zeroed]: mem::MaybeUninit::zeroed
#[unstable(feature = "allocator_api", issue = "32838")]
#[inline]
pub fn try_new_zeroed_slice(len: usize) -> Result<Box<[mem::MaybeUninit<T>]>, AllocError> {
let ptr = if T::IS_ZST || len == 0 {
NonNull::dangling()
} else {
let layout = match Layout::array::<mem::MaybeUninit<T>>(len) {
Ok(l) => l,
Err(_) => return Err(AllocError),
};
Global.allocate_zeroed(layout)?.cast()
};
unsafe { Ok(RawVec::from_raw_parts_in(ptr.as_ptr(), len, Global).into_box(len)) }
}
}
impl<T, A: Allocator> Box<[T], A> {
/// Constructs a new boxed slice with uninitialized contents in the provided allocator.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api, new_uninit)]
///
/// use std::alloc::System;
///
/// let mut values = Box::<[u32], _>::new_uninit_slice_in(3, System);
///
/// let values = unsafe {
/// // Deferred initialization:
/// values[0].as_mut_ptr().write(1);
/// values[1].as_mut_ptr().write(2);
/// values[2].as_mut_ptr().write(3);
///
/// values.assume_init()
/// };
///
/// assert_eq!(*values, [1, 2, 3])
/// ```
#[cfg(not(no_global_oom_handling))]
#[unstable(feature = "allocator_api", issue = "32838")]
// #[unstable(feature = "new_uninit", issue = "63291")]
#[must_use]
pub fn new_uninit_slice_in(len: usize, alloc: A) -> Box<[mem::MaybeUninit<T>], A> {
unsafe { RawVec::with_capacity_in(len, alloc).into_box(len) }
}
/// Constructs a new boxed slice with uninitialized contents in the provided allocator,
/// with the memory being filled with `0` bytes.
///
/// See [`MaybeUninit::zeroed`][zeroed] for examples of correct and incorrect usage
/// of this method.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api, new_uninit)]
///
/// use std::alloc::System;
///
/// let values = Box::<[u32], _>::new_zeroed_slice_in(3, System);
/// let values = unsafe { values.assume_init() };
///
/// assert_eq!(*values, [0, 0, 0])
/// ```
///
/// [zeroed]: mem::MaybeUninit::zeroed
#[cfg(not(no_global_oom_handling))]
#[unstable(feature = "allocator_api", issue = "32838")]
// #[unstable(feature = "new_uninit", issue = "63291")]
#[must_use]
pub fn new_zeroed_slice_in(len: usize, alloc: A) -> Box<[mem::MaybeUninit<T>], A> {
unsafe { RawVec::with_capacity_zeroed_in(len, alloc).into_box(len) }
}
}
impl<T, A: Allocator> Box<mem::MaybeUninit<T>, A> {
/// Converts to `Box<T, A>`.
///
/// # Safety
///
/// As with [`MaybeUninit::assume_init`],
/// it is up to the caller to guarantee that the value
/// really is in an initialized state.
/// Calling this when the content is not yet fully initialized
/// causes immediate undefined behavior.
///
/// [`MaybeUninit::assume_init`]: mem::MaybeUninit::assume_init
///
/// # Examples
///
/// ```
/// #![feature(new_uninit)]
///
/// let mut five = Box::<u32>::new_uninit();
///
/// let five: Box<u32> = unsafe {
/// // Deferred initialization:
/// five.as_mut_ptr().write(5);
///
/// five.assume_init()
/// };
///
/// assert_eq!(*five, 5)
/// ```
#[unstable(feature = "new_uninit", issue = "63291")]
#[inline]
pub unsafe fn assume_init(self) -> Box<T, A> {
let (raw, alloc) = Box::into_raw_with_allocator(self);
unsafe { Box::from_raw_in(raw as *mut T, alloc) }
}
/// Writes the value and converts to `Box<T, A>`.
///
/// This method converts the box similarly to [`Box::assume_init`] but
/// writes `value` into it before conversion thus guaranteeing safety.
/// In some scenarios use of this method may improve performance because
/// the compiler may be able to optimize copying from stack.
///
/// # Examples
///
/// ```
/// #![feature(new_uninit)]
///
/// let big_box = Box::<[usize; 1024]>::new_uninit();
///
/// let mut array = [0; 1024];
/// for (i, place) in array.iter_mut().enumerate() {
/// *place = i;
/// }
///
/// // The optimizer may be able to elide this copy, so previous code writes
/// // to heap directly.
/// let big_box = Box::write(big_box, array);
///
/// for (i, x) in big_box.iter().enumerate() {
/// assert_eq!(*x, i);
/// }
/// ```
#[unstable(feature = "new_uninit", issue = "63291")]
#[inline]
pub fn write(mut boxed: Self, value: T) -> Box<T, A> {
unsafe {
(*boxed).write(value);
boxed.assume_init()
}
}
}
impl<T, A: Allocator> Box<[mem::MaybeUninit<T>], A> {
/// Converts to `Box<[T], A>`.
///
/// # Safety
///
/// As with [`MaybeUninit::assume_init`],
/// it is up to the caller to guarantee that the values
/// really are in an initialized state.
/// Calling this when the content is not yet fully initialized
/// causes immediate undefined behavior.
///
/// [`MaybeUninit::assume_init`]: mem::MaybeUninit::assume_init
///
/// # Examples
///
/// ```
/// #![feature(new_uninit)]
///
/// let mut values = Box::<[u32]>::new_uninit_slice(3);
///
/// let values = unsafe {
/// // Deferred initialization:
/// values[0].as_mut_ptr().write(1);
/// values[1].as_mut_ptr().write(2);
/// values[2].as_mut_ptr().write(3);
///
/// values.assume_init()
/// };
///
/// assert_eq!(*values, [1, 2, 3])
/// ```
#[unstable(feature = "new_uninit", issue = "63291")]
#[inline]
pub unsafe fn assume_init(self) -> Box<[T], A> {
let (raw, alloc) = Box::into_raw_with_allocator(self);
unsafe { Box::from_raw_in(raw as *mut [T], alloc) }
}
}
impl<T: ?Sized> Box<T> {
/// Constructs a box from a raw pointer.
///
/// After calling this function, the raw pointer is owned by the
/// resulting `Box`. Specifically, the `Box` destructor will call
/// the destructor of `T` and free the allocated memory. For this
/// to be safe, the memory must have been allocated in accordance
/// with the [memory layout] used by `Box` .
///
/// # Safety
///
/// This function is unsafe because improper use may lead to
/// memory problems. For example, a double-free may occur if the
/// function is called twice on the same raw pointer.
///
/// The safety conditions are described in the [memory layout] section.
///
/// # Examples
///
/// Recreate a `Box` which was previously converted to a raw pointer
/// using [`Box::into_raw`]:
/// ```
/// let x = Box::new(5);
/// let ptr = Box::into_raw(x);
/// let x = unsafe { Box::from_raw(ptr) };
/// ```
/// Manually create a `Box` from scratch by using the global allocator:
/// ```
/// use std::alloc::{alloc, Layout};
///
/// unsafe {
/// let ptr = alloc(Layout::new::<i32>()) as *mut i32;
/// // In general .write is required to avoid attempting to destruct
/// // the (uninitialized) previous contents of `ptr`, though for this
/// // simple example `*ptr = 5` would have worked as well.
/// ptr.write(5);
/// let x = Box::from_raw(ptr);
/// }
/// ```
///
/// [memory layout]: self#memory-layout
/// [`Layout`]: crate::Layout
#[stable(feature = "box_raw", since = "1.4.0")]
#[inline]
#[must_use = "call `drop(Box::from_raw(ptr))` if you intend to drop the `Box`"]
pub unsafe fn from_raw(raw: *mut T) -> Self {
unsafe { Self::from_raw_in(raw, Global) }
}
}
impl<T: ?Sized, A: Allocator> Box<T, A> {
/// Constructs a box from a raw pointer in the given allocator.
///
/// After calling this function, the raw pointer is owned by the
/// resulting `Box`. Specifically, the `Box` destructor will call
/// the destructor of `T` and free the allocated memory. For this
/// to be safe, the memory must have been allocated in accordance
/// with the [memory layout] used by `Box` .
///
/// # Safety
///
/// This function is unsafe because improper use may lead to
/// memory problems. For example, a double-free may occur if the
/// function is called twice on the same raw pointer.
///
///
/// # Examples
///
/// Recreate a `Box` which was previously converted to a raw pointer
/// using [`Box::into_raw_with_allocator`]:
/// ```
/// #![feature(allocator_api)]
///
/// use std::alloc::System;
///
/// let x = Box::new_in(5, System);
/// let (ptr, alloc) = Box::into_raw_with_allocator(x);
/// let x = unsafe { Box::from_raw_in(ptr, alloc) };
/// ```
/// Manually create a `Box` from scratch by using the system allocator:
/// ```
/// #![feature(allocator_api, slice_ptr_get)]
///
/// use std::alloc::{Allocator, Layout, System};
///
/// unsafe {
/// let ptr = System.allocate(Layout::new::<i32>())?.as_mut_ptr() as *mut i32;
/// // In general .write is required to avoid attempting to destruct
/// // the (uninitialized) previous contents of `ptr`, though for this
/// // simple example `*ptr = 5` would have worked as well.
/// ptr.write(5);
/// let x = Box::from_raw_in(ptr, System);
/// }
/// # Ok::<(), std::alloc::AllocError>(())
/// ```
///
/// [memory layout]: self#memory-layout
/// [`Layout`]: crate::Layout
#[unstable(feature = "allocator_api", issue = "32838")]
#[rustc_const_unstable(feature = "const_box", issue = "92521")]
#[inline]
pub const unsafe fn from_raw_in(raw: *mut T, alloc: A) -> Self {
Box(unsafe { Unique::new_unchecked(raw) }, alloc)
}
/// Consumes the `Box`, returning a wrapped raw pointer.
///
/// The pointer will be properly aligned and non-null.
///
/// After calling this function, the caller is responsible for the
/// memory previously managed by the `Box`. In particular, the
/// caller should properly destroy `T` and release the memory, taking
/// into account the [memory layout] used by `Box`. The easiest way to
/// do this is to convert the raw pointer back into a `Box` with the
/// [`Box::from_raw`] function, allowing the `Box` destructor to perform
/// the cleanup.
///
/// Note: this is an associated function, which means that you have
/// to call it as `Box::into_raw(b)` instead of `b.into_raw()`. This
/// is so that there is no conflict with a method on the inner type.
///
/// # Examples
/// Converting the raw pointer back into a `Box` with [`Box::from_raw`]
/// for automatic cleanup:
/// ```
/// let x = Box::new(String::from("Hello"));
/// let ptr = Box::into_raw(x);
/// let x = unsafe { Box::from_raw(ptr) };
/// ```
/// Manual cleanup by explicitly running the destructor and deallocating
/// the memory:
/// ```
/// use std::alloc::{dealloc, Layout};
/// use std::ptr;
///
/// let x = Box::new(String::from("Hello"));
/// let ptr = Box::into_raw(x);
/// unsafe {
/// ptr::drop_in_place(ptr);
/// dealloc(ptr as *mut u8, Layout::new::<String>());
/// }
/// ```
/// Note: This is equivalent to the following:
/// ```
/// let x = Box::new(String::from("Hello"));
/// let ptr = Box::into_raw(x);
/// unsafe {
/// drop(Box::from_raw(ptr));
/// }
/// ```
///
/// [memory layout]: self#memory-layout
#[stable(feature = "box_raw", since = "1.4.0")]
#[inline]
pub fn into_raw(b: Self) -> *mut T {
Self::into_raw_with_allocator(b).0
}
/// Consumes the `Box`, returning a wrapped raw pointer and the allocator.
///
/// The pointer will be properly aligned and non-null.
///
/// After calling this function, the caller is responsible for the
/// memory previously managed by the `Box`. In particular, the
/// caller should properly destroy `T` and release the memory, taking
/// into account the [memory layout] used by `Box`. The easiest way to
/// do this is to convert the raw pointer back into a `Box` with the
/// [`Box::from_raw_in`] function, allowing the `Box` destructor to perform
/// the cleanup.
///
/// Note: this is an associated function, which means that you have
/// to call it as `Box::into_raw_with_allocator(b)` instead of `b.into_raw_with_allocator()`. This
/// is so that there is no conflict with a method on the inner type.
///
/// # Examples
/// Converting the raw pointer back into a `Box` with [`Box::from_raw_in`]
/// for automatic cleanup:
/// ```
/// #![feature(allocator_api)]
///
/// use std::alloc::System;
///
/// let x = Box::new_in(String::from("Hello"), System);
/// let (ptr, alloc) = Box::into_raw_with_allocator(x);
/// let x = unsafe { Box::from_raw_in(ptr, alloc) };
/// ```
/// Manual cleanup by explicitly running the destructor and deallocating
/// the memory:
/// ```
/// #![feature(allocator_api)]
///
/// use std::alloc::{Allocator, Layout, System};
/// use std::ptr::{self, NonNull};
///
/// let x = Box::new_in(String::from("Hello"), System);
/// let (ptr, alloc) = Box::into_raw_with_allocator(x);
/// unsafe {
/// ptr::drop_in_place(ptr);
/// let non_null = NonNull::new_unchecked(ptr);
/// alloc.deallocate(non_null.cast(), Layout::new::<String>());
/// }
/// ```
///
/// [memory layout]: self#memory-layout
#[unstable(feature = "allocator_api", issue = "32838")]
#[inline]
pub fn into_raw_with_allocator(b: Self) -> (*mut T, A) {
let (leaked, alloc) = Box::into_unique(b);
(leaked.as_ptr(), alloc)
}
#[unstable(
feature = "ptr_internals",
issue = "none",
reason = "use `Box::leak(b).into()` or `Unique::from(Box::leak(b))` instead"
)]
#[inline]
#[doc(hidden)]
pub fn into_unique(b: Self) -> (Unique<T>, A) {
// Box is recognized as a "unique pointer" by Stacked Borrows, but internally it is a
// raw pointer for the type system. Turning it directly into a raw pointer would not be
// recognized as "releasing" the unique pointer to permit aliased raw accesses,
// so all raw pointer methods have to go through `Box::leak`. Turning *that* to a raw pointer
// behaves correctly.
let alloc = unsafe { ptr::read(&b.1) };
(Unique::from(Box::leak(b)), alloc)
}
/// Returns a reference to the underlying allocator.
///
/// Note: this is an associated function, which means that you have
/// to call it as `Box::allocator(&b)` instead of `b.allocator()`. This
/// is so that there is no conflict with a method on the inner type.
#[unstable(feature = "allocator_api", issue = "32838")]
#[rustc_const_unstable(feature = "const_box", issue = "92521")]
#[inline]
pub const fn allocator(b: &Self) -> &A {
&b.1
}
/// Consumes and leaks the `Box`, returning a mutable reference,
/// `&'a mut T`. Note that the type `T` must outlive the chosen lifetime
/// `'a`. If the type has only static references, or none at all, then this
/// may be chosen to be `'static`.
///
/// This function is mainly useful for data that lives for the remainder of
/// the program's life. Dropping the returned reference will cause a memory
/// leak. If this is not acceptable, the reference should first be wrapped
/// with the [`Box::from_raw`] function producing a `Box`. This `Box` can
/// then be dropped which will properly destroy `T` and release the
/// allocated memory.
///
/// Note: this is an associated function, which means that you have
/// to call it as `Box::leak(b)` instead of `b.leak()`. This
/// is so that there is no conflict with a method on the inner type.
///
/// # Examples
///
/// Simple usage:
///
/// ```
/// let x = Box::new(41);
/// let static_ref: &'static mut usize = Box::leak(x);
/// *static_ref += 1;
/// assert_eq!(*static_ref, 42);
/// ```
///
/// Unsized data:
///
/// ```
/// let x = vec![1, 2, 3].into_boxed_slice();
/// let static_ref = Box::leak(x);
/// static_ref[0] = 4;
/// assert_eq!(*static_ref, [4, 2, 3]);
/// ```
#[stable(feature = "box_leak", since = "1.26.0")]
#[inline]
pub fn leak<'a>(b: Self) -> &'a mut T
where
A: 'a,
{
unsafe { &mut *mem::ManuallyDrop::new(b).0.as_ptr() }
}
/// Converts a `Box<T>` into a `Pin<Box<T>>`. If `T` does not implement [`Unpin`], then
/// `*boxed` will be pinned in memory and unable to be moved.
///
/// This conversion does not allocate on the heap and happens in place.
///
/// This is also available via [`From`].
///
/// Constructing and pinning a `Box` with <code>Box::into_pin([Box::new]\(x))</code>
/// can also be written more concisely using <code>[Box::pin]\(x)</code>.
/// This `into_pin` method is useful if you already have a `Box<T>`, or you are
/// constructing a (pinned) `Box` in a different way than with [`Box::new`].
///
/// # Notes
///
/// It's not recommended that crates add an impl like `From<Box<T>> for Pin<T>`,
/// as it'll introduce an ambiguity when calling `Pin::from`.
/// A demonstration of such a poor impl is shown below.
///
/// ```compile_fail
/// # use std::pin::Pin;
/// struct Foo; // A type defined in this crate.
/// impl From<Box<()>> for Pin<Foo> {
/// fn from(_: Box<()>) -> Pin<Foo> {
/// Pin::new(Foo)
/// }
/// }
///
/// let foo = Box::new(());
/// let bar = Pin::from(foo);
/// ```
#[stable(feature = "box_into_pin", since = "1.63.0")]
#[rustc_const_unstable(feature = "const_box", issue = "92521")]
pub const fn into_pin(boxed: Self) -> Pin<Self>
where
A: 'static,
{
// It's not possible to move or replace the insides of a `Pin<Box<T>>`
// when `T: !Unpin`, so it's safe to pin it directly without any
// additional requirements.
unsafe { Pin::new_unchecked(boxed) }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
unsafe impl<#[may_dangle] T: ?Sized, A: Allocator> Drop for Box<T, A> {
#[inline]
fn drop(&mut self) {
// the T in the Box is dropped by the compiler before the destructor is run
let ptr = self.0;
unsafe {
let layout = Layout::for_value_raw(ptr.as_ptr());
if layout.size() != 0 {
self.1.deallocate(From::from(ptr.cast()), layout);
}
}
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: Default> Default for Box<T> {
/// Creates a `Box<T>`, with the `Default` value for T.
#[inline]
fn default() -> Self {
Box::new(T::default())
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> Default for Box<[T]> {
#[inline]
fn default() -> Self {
let ptr: Unique<[T]> = Unique::<[T; 0]>::dangling();
Box(ptr, Global)
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "default_box_extra", since = "1.17.0")]
impl Default for Box<str> {
#[inline]
fn default() -> Self {
// SAFETY: This is the same as `Unique::cast<U>` but with an unsized `U = str`.
let ptr: Unique<str> = unsafe {
let bytes: Unique<[u8]> = Unique::<[u8; 0]>::dangling();
Unique::new_unchecked(bytes.as_ptr() as *mut str)
};
Box(ptr, Global)
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: Clone, A: Allocator + Clone> Clone for Box<T, A> {
/// Returns a new box with a `clone()` of this box's contents.
///
/// # Examples
///
/// ```
/// let x = Box::new(5);
/// let y = x.clone();
///
/// // The value is the same
/// assert_eq!(x, y);
///
/// // But they are unique objects
/// assert_ne!(&*x as *const i32, &*y as *const i32);
/// ```
#[inline]
fn clone(&self) -> Self {
// Pre-allocate memory to allow writing the cloned value directly.
let mut boxed = Self::new_uninit_in(self.1.clone());
unsafe {
(**self).write_clone_into_raw(boxed.as_mut_ptr());
boxed.assume_init()
}
}
/// Copies `source`'s contents into `self` without creating a new allocation.
///
/// # Examples
///
/// ```
/// let x = Box::new(5);
/// let mut y = Box::new(10);
/// let yp: *const i32 = &*y;
///
/// y.clone_from(&x);
///
/// // The value is the same
/// assert_eq!(x, y);
///
/// // And no allocation occurred
/// assert_eq!(yp, &*y);
/// ```
#[inline]
fn clone_from(&mut self, source: &Self) {
(**self).clone_from(&(**source));
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "box_slice_clone", since = "1.3.0")]
impl Clone for Box<str> {
fn clone(&self) -> Self {
// this makes a copy of the data
let buf: Box<[u8]> = self.as_bytes().into();
unsafe { from_boxed_utf8_unchecked(buf) }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized + PartialEq, A: Allocator> PartialEq for Box<T, A> {
#[inline]
fn eq(&self, other: &Self) -> bool {
PartialEq::eq(&**self, &**other)
}
#[inline]
fn ne(&self, other: &Self) -> bool {
PartialEq::ne(&**self, &**other)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized + PartialOrd, A: Allocator> PartialOrd for Box<T, A> {
#[inline]
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
PartialOrd::partial_cmp(&**self, &**other)
}
#[inline]
fn lt(&self, other: &Self) -> bool {
PartialOrd::lt(&**self, &**other)
}
#[inline]
fn le(&self, other: &Self) -> bool {
PartialOrd::le(&**self, &**other)
}
#[inline]
fn ge(&self, other: &Self) -> bool {
PartialOrd::ge(&**self, &**other)
}
#[inline]
fn gt(&self, other: &Self) -> bool {
PartialOrd::gt(&**self, &**other)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized + Ord, A: Allocator> Ord for Box<T, A> {
#[inline]
fn cmp(&self, other: &Self) -> Ordering {
Ord::cmp(&**self, &**other)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized + Eq, A: Allocator> Eq for Box<T, A> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized + Hash, A: Allocator> Hash for Box<T, A> {
fn hash<H: Hasher>(&self, state: &mut H) {
(**self).hash(state);
}
}
#[stable(feature = "indirect_hasher_impl", since = "1.22.0")]
impl<T: ?Sized + Hasher, A: Allocator> Hasher for Box<T, A> {
fn finish(&self) -> u64 {
(**self).finish()
}
fn write(&mut self, bytes: &[u8]) {
(**self).write(bytes)
}
fn write_u8(&mut self, i: u8) {
(**self).write_u8(i)
}
fn write_u16(&mut self, i: u16) {
(**self).write_u16(i)
}
fn write_u32(&mut self, i: u32) {
(**self).write_u32(i)
}
fn write_u64(&mut self, i: u64) {
(**self).write_u64(i)
}
fn write_u128(&mut self, i: u128) {
(**self).write_u128(i)
}
fn write_usize(&mut self, i: usize) {
(**self).write_usize(i)
}
fn write_i8(&mut self, i: i8) {
(**self).write_i8(i)
}
fn write_i16(&mut self, i: i16) {
(**self).write_i16(i)
}
fn write_i32(&mut self, i: i32) {
(**self).write_i32(i)
}
fn write_i64(&mut self, i: i64) {
(**self).write_i64(i)
}
fn write_i128(&mut self, i: i128) {
(**self).write_i128(i)
}
fn write_isize(&mut self, i: isize) {
(**self).write_isize(i)
}
fn write_length_prefix(&mut self, len: usize) {
(**self).write_length_prefix(len)
}
fn write_str(&mut self, s: &str) {
(**self).write_str(s)
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "from_for_ptrs", since = "1.6.0")]
impl<T> From<T> for Box<T> {
/// Converts a `T` into a `Box<T>`
///
/// The conversion allocates on the heap and moves `t`
/// from the stack into it.
///
/// # Examples
///
/// ```rust
/// let x = 5;
/// let boxed = Box::new(5);
///
/// assert_eq!(Box::from(x), boxed);
/// ```
fn from(t: T) -> Self {
Box::new(t)
}
}
#[stable(feature = "pin", since = "1.33.0")]
impl<T: ?Sized, A: Allocator> From<Box<T, A>> for Pin<Box<T, A>>
where
A: 'static,
{
/// Converts a `Box<T>` into a `Pin<Box<T>>`. If `T` does not implement [`Unpin`], then
/// `*boxed` will be pinned in memory and unable to be moved.
///
/// This conversion does not allocate on the heap and happens in place.
///
/// This is also available via [`Box::into_pin`].
///
/// Constructing and pinning a `Box` with <code><Pin<Box\<T>>>::from([Box::new]\(x))</code>
/// can also be written more concisely using <code>[Box::pin]\(x)</code>.
/// This `From` implementation is useful if you already have a `Box<T>`, or you are
/// constructing a (pinned) `Box` in a different way than with [`Box::new`].
fn from(boxed: Box<T, A>) -> Self {
Box::into_pin(boxed)
}
}
/// Specialization trait used for `From<&[T]>`.
#[cfg(not(no_global_oom_handling))]
trait BoxFromSlice<T> {
fn from_slice(slice: &[T]) -> Self;
}
#[cfg(not(no_global_oom_handling))]
impl<T: Clone> BoxFromSlice<T> for Box<[T]> {
#[inline]
default fn from_slice(slice: &[T]) -> Self {
slice.to_vec().into_boxed_slice()
}
}
#[cfg(not(no_global_oom_handling))]
impl<T: Copy> BoxFromSlice<T> for Box<[T]> {
#[inline]
fn from_slice(slice: &[T]) -> Self {
let len = slice.len();
let buf = RawVec::with_capacity(len);
unsafe {
ptr::copy_nonoverlapping(slice.as_ptr(), buf.ptr(), len);
buf.into_box(slice.len()).assume_init()
}
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "box_from_slice", since = "1.17.0")]
impl<T: Clone> From<&[T]> for Box<[T]> {
/// Converts a `&[T]` into a `Box<[T]>`
///
/// This conversion allocates on the heap
/// and performs a copy of `slice` and its contents.
///
/// # Examples
/// ```rust
/// // create a &[u8] which will be used to create a Box<[u8]>
/// let slice: &[u8] = &[104, 101, 108, 108, 111];
/// let boxed_slice: Box<[u8]> = Box::from(slice);
///
/// println!("{boxed_slice:?}");
/// ```
#[inline]
fn from(slice: &[T]) -> Box<[T]> {
<Self as BoxFromSlice<T>>::from_slice(slice)
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "box_from_cow", since = "1.45.0")]
impl<T: Clone> From<Cow<'_, [T]>> for Box<[T]> {
/// Converts a `Cow<'_, [T]>` into a `Box<[T]>`
///
/// When `cow` is the `Cow::Borrowed` variant, this
/// conversion allocates on the heap and copies the
/// underlying slice. Otherwise, it will try to reuse the owned
/// `Vec`'s allocation.
#[inline]
fn from(cow: Cow<'_, [T]>) -> Box<[T]> {
match cow {
Cow::Borrowed(slice) => Box::from(slice),
Cow::Owned(slice) => Box::from(slice),
}
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "box_from_slice", since = "1.17.0")]
impl From<&str> for Box<str> {
/// Converts a `&str` into a `Box<str>`
///
/// This conversion allocates on the heap
/// and performs a copy of `s`.
///
/// # Examples
///
/// ```rust
/// let boxed: Box<str> = Box::from("hello");
/// println!("{boxed}");
/// ```
#[inline]
fn from(s: &str) -> Box<str> {
unsafe { from_boxed_utf8_unchecked(Box::from(s.as_bytes())) }
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "box_from_cow", since = "1.45.0")]
impl From<Cow<'_, str>> for Box<str> {
/// Converts a `Cow<'_, str>` into a `Box<str>`
///
/// When `cow` is the `Cow::Borrowed` variant, this
/// conversion allocates on the heap and copies the
/// underlying `str`. Otherwise, it will try to reuse the owned
/// `String`'s allocation.
///
/// # Examples
///
/// ```rust
/// use std::borrow::Cow;
///
/// let unboxed = Cow::Borrowed("hello");
/// let boxed: Box<str> = Box::from(unboxed);
/// println!("{boxed}");
/// ```
///
/// ```rust
/// # use std::borrow::Cow;
/// let unboxed = Cow::Owned("hello".to_string());
/// let boxed: Box<str> = Box::from(unboxed);
/// println!("{boxed}");
/// ```
#[inline]
fn from(cow: Cow<'_, str>) -> Box<str> {
match cow {
Cow::Borrowed(s) => Box::from(s),
Cow::Owned(s) => Box::from(s),
}
}
}
#[stable(feature = "boxed_str_conv", since = "1.19.0")]
impl<A: Allocator> From<Box<str, A>> for Box<[u8], A> {
/// Converts a `Box<str>` into a `Box<[u8]>`
///
/// This conversion does not allocate on the heap and happens in place.
///
/// # Examples
/// ```rust
/// // create a Box<str> which will be used to create a Box<[u8]>
/// let boxed: Box<str> = Box::from("hello");
/// let boxed_str: Box<[u8]> = Box::from(boxed);
///
/// // create a &[u8] which will be used to create a Box<[u8]>
/// let slice: &[u8] = &[104, 101, 108, 108, 111];
/// let boxed_slice = Box::from(slice);
///
/// assert_eq!(boxed_slice, boxed_str);
/// ```
#[inline]
fn from(s: Box<str, A>) -> Self {
let (raw, alloc) = Box::into_raw_with_allocator(s);
unsafe { Box::from_raw_in(raw as *mut [u8], alloc) }
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "box_from_array", since = "1.45.0")]
impl<T, const N: usize> From<[T; N]> for Box<[T]> {
/// Converts a `[T; N]` into a `Box<[T]>`
///
/// This conversion moves the array to newly heap-allocated memory.
///
/// # Examples
///
/// ```rust
/// let boxed: Box<[u8]> = Box::from([4, 2]);
/// println!("{boxed:?}");
/// ```
fn from(array: [T; N]) -> Box<[T]> {
Box::new(array)
}
}
/// Casts a boxed slice to a boxed array.
///
/// # Safety
///
/// `boxed_slice.len()` must be exactly `N`.
unsafe fn boxed_slice_as_array_unchecked<T, A: Allocator, const N: usize>(
boxed_slice: Box<[T], A>,
) -> Box<[T; N], A> {
debug_assert_eq!(boxed_slice.len(), N);
let (ptr, alloc) = Box::into_raw_with_allocator(boxed_slice);
// SAFETY: Pointer and allocator came from an existing box,
// and our safety condition requires that the length is exactly `N`
unsafe { Box::from_raw_in(ptr as *mut [T; N], alloc) }
}
#[stable(feature = "boxed_slice_try_from", since = "1.43.0")]
impl<T, const N: usize> TryFrom<Box<[T]>> for Box<[T; N]> {
type Error = Box<[T]>;
/// Attempts to convert a `Box<[T]>` into a `Box<[T; N]>`.
///
/// The conversion occurs in-place and does not require a
/// new memory allocation.
///
/// # Errors
///
/// Returns the old `Box<[T]>` in the `Err` variant if
/// `boxed_slice.len()` does not equal `N`.
fn try_from(boxed_slice: Box<[T]>) -> Result<Self, Self::Error> {
if boxed_slice.len() == N {
Ok(unsafe { boxed_slice_as_array_unchecked(boxed_slice) })
} else {
Err(boxed_slice)
}
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "boxed_array_try_from_vec", since = "1.66.0")]
impl<T, const N: usize> TryFrom<Vec<T>> for Box<[T; N]> {
type Error = Vec<T>;
/// Attempts to convert a `Vec<T>` into a `Box<[T; N]>`.
///
/// Like [`Vec::into_boxed_slice`], this is in-place if `vec.capacity() == N`,
/// but will require a reallocation otherwise.
///
/// # Errors
///
/// Returns the original `Vec<T>` in the `Err` variant if
/// `boxed_slice.len()` does not equal `N`.
///
/// # Examples
///
/// This can be used with [`vec!`] to create an array on the heap:
///
/// ```
/// let state: Box<[f32; 100]> = vec![1.0; 100].try_into().unwrap();
/// assert_eq!(state.len(), 100);
/// ```
fn try_from(vec: Vec<T>) -> Result<Self, Self::Error> {
if vec.len() == N {
let boxed_slice = vec.into_boxed_slice();
Ok(unsafe { boxed_slice_as_array_unchecked(boxed_slice) })
} else {
Err(vec)
}
}
}
impl<A: Allocator> Box<dyn Any, A> {
/// Attempt to downcast the box to a concrete type.
///
/// # Examples
///
/// ```
/// use std::any::Any;
///
/// fn print_if_string(value: Box<dyn Any>) {
/// if let Ok(string) = value.downcast::<String>() {
/// println!("String ({}): {}", string.len(), string);
/// }
/// }
///
/// let my_string = "Hello World".to_string();
/// print_if_string(Box::new(my_string));
/// print_if_string(Box::new(0i8));
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn downcast<T: Any>(self) -> Result<Box<T, A>, Self> {
if self.is::<T>() { unsafe { Ok(self.downcast_unchecked::<T>()) } } else { Err(self) }
}
/// Downcasts the box to a concrete type.
///
/// For a safe alternative see [`downcast`].
///
/// # Examples
///
/// ```
/// #![feature(downcast_unchecked)]
///
/// use std::any::Any;
///
/// let x: Box<dyn Any> = Box::new(1_usize);
///
/// unsafe {
/// assert_eq!(*x.downcast_unchecked::<usize>(), 1);
/// }
/// ```
///
/// # Safety
///
/// The contained value must be of type `T`. Calling this method
/// with the incorrect type is *undefined behavior*.
///
/// [`downcast`]: Self::downcast
#[inline]
#[unstable(feature = "downcast_unchecked", issue = "90850")]
pub unsafe fn downcast_unchecked<T: Any>(self) -> Box<T, A> {
debug_assert!(self.is::<T>());
unsafe {
let (raw, alloc): (*mut dyn Any, _) = Box::into_raw_with_allocator(self);
Box::from_raw_in(raw as *mut T, alloc)
}
}
}
impl<A: Allocator> Box<dyn Any + Send, A> {
/// Attempt to downcast the box to a concrete type.
///
/// # Examples
///
/// ```
/// use std::any::Any;
///
/// fn print_if_string(value: Box<dyn Any + Send>) {
/// if let Ok(string) = value.downcast::<String>() {
/// println!("String ({}): {}", string.len(), string);
/// }
/// }
///
/// let my_string = "Hello World".to_string();
/// print_if_string(Box::new(my_string));
/// print_if_string(Box::new(0i8));
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn downcast<T: Any>(self) -> Result<Box<T, A>, Self> {
if self.is::<T>() { unsafe { Ok(self.downcast_unchecked::<T>()) } } else { Err(self) }
}
/// Downcasts the box to a concrete type.
///
/// For a safe alternative see [`downcast`].
///
/// # Examples
///
/// ```
/// #![feature(downcast_unchecked)]
///
/// use std::any::Any;
///
/// let x: Box<dyn Any + Send> = Box::new(1_usize);
///
/// unsafe {
/// assert_eq!(*x.downcast_unchecked::<usize>(), 1);
/// }
/// ```
///
/// # Safety
///
/// The contained value must be of type `T`. Calling this method
/// with the incorrect type is *undefined behavior*.
///
/// [`downcast`]: Self::downcast
#[inline]
#[unstable(feature = "downcast_unchecked", issue = "90850")]
pub unsafe fn downcast_unchecked<T: Any>(self) -> Box<T, A> {
debug_assert!(self.is::<T>());
unsafe {
let (raw, alloc): (*mut (dyn Any + Send), _) = Box::into_raw_with_allocator(self);
Box::from_raw_in(raw as *mut T, alloc)
}
}
}
impl<A: Allocator> Box<dyn Any + Send + Sync, A> {
/// Attempt to downcast the box to a concrete type.
///
/// # Examples
///
/// ```
/// use std::any::Any;
///
/// fn print_if_string(value: Box<dyn Any + Send + Sync>) {
/// if let Ok(string) = value.downcast::<String>() {
/// println!("String ({}): {}", string.len(), string);
/// }
/// }
///
/// let my_string = "Hello World".to_string();
/// print_if_string(Box::new(my_string));
/// print_if_string(Box::new(0i8));
/// ```
#[inline]
#[stable(feature = "box_send_sync_any_downcast", since = "1.51.0")]
pub fn downcast<T: Any>(self) -> Result<Box<T, A>, Self> {
if self.is::<T>() { unsafe { Ok(self.downcast_unchecked::<T>()) } } else { Err(self) }
}
/// Downcasts the box to a concrete type.
///
/// For a safe alternative see [`downcast`].
///
/// # Examples
///
/// ```
/// #![feature(downcast_unchecked)]
///
/// use std::any::Any;
///
/// let x: Box<dyn Any + Send + Sync> = Box::new(1_usize);
///
/// unsafe {
/// assert_eq!(*x.downcast_unchecked::<usize>(), 1);
/// }
/// ```
///
/// # Safety
///
/// The contained value must be of type `T`. Calling this method
/// with the incorrect type is *undefined behavior*.
///
/// [`downcast`]: Self::downcast
#[inline]
#[unstable(feature = "downcast_unchecked", issue = "90850")]
pub unsafe fn downcast_unchecked<T: Any>(self) -> Box<T, A> {
debug_assert!(self.is::<T>());
unsafe {
let (raw, alloc): (*mut (dyn Any + Send + Sync), _) =
Box::into_raw_with_allocator(self);
Box::from_raw_in(raw as *mut T, alloc)
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: fmt::Display + ?Sized, A: Allocator> fmt::Display for Box<T, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&**self, f)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: fmt::Debug + ?Sized, A: Allocator> fmt::Debug for Box<T, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&**self, f)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized, A: Allocator> fmt::Pointer for Box<T, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// It's not possible to extract the inner Uniq directly from the Box,
// instead we cast it to a *const which aliases the Unique
let ptr: *const T = &**self;
fmt::Pointer::fmt(&ptr, f)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized, A: Allocator> Deref for Box<T, A> {
type Target = T;
fn deref(&self) -> &T {
&**self
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: ?Sized, A: Allocator> DerefMut for Box<T, A> {
fn deref_mut(&mut self) -> &mut T {
&mut **self
}
}
#[unstable(feature = "receiver_trait", issue = "none")]
impl<T: ?Sized, A: Allocator> Receiver for Box<T, A> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<I: Iterator + ?Sized, A: Allocator> Iterator for Box<I, A> {
type Item = I::Item;
fn next(&mut self) -> Option<I::Item> {
(**self).next()
}
fn size_hint(&self) -> (usize, Option<usize>) {
(**self).size_hint()
}
fn nth(&mut self, n: usize) -> Option<I::Item> {
(**self).nth(n)
}
fn last(self) -> Option<I::Item> {
BoxIter::last(self)
}
}
trait BoxIter {
type Item;
fn last(self) -> Option<Self::Item>;
}
impl<I: Iterator + ?Sized, A: Allocator> BoxIter for Box<I, A> {
type Item = I::Item;
default fn last(self) -> Option<I::Item> {
#[inline]
fn some<T>(_: Option<T>, x: T) -> Option<T> {
Some(x)
}
self.fold(None, some)
}
}
/// Specialization for sized `I`s that uses `I`s implementation of `last()`
/// instead of the default.
#[stable(feature = "rust1", since = "1.0.0")]
impl<I: Iterator, A: Allocator> BoxIter for Box<I, A> {
fn last(self) -> Option<I::Item> {
(*self).last()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<I: DoubleEndedIterator + ?Sized, A: Allocator> DoubleEndedIterator for Box<I, A> {
fn next_back(&mut self) -> Option<I::Item> {
(**self).next_back()
}
fn nth_back(&mut self, n: usize) -> Option<I::Item> {
(**self).nth_back(n)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<I: ExactSizeIterator + ?Sized, A: Allocator> ExactSizeIterator for Box<I, A> {
fn len(&self) -> usize {
(**self).len()
}
fn is_empty(&self) -> bool {
(**self).is_empty()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<I: FusedIterator + ?Sized, A: Allocator> FusedIterator for Box<I, A> {}
#[stable(feature = "boxed_closure_impls", since = "1.35.0")]
impl<Args: Tuple, F: FnOnce<Args> + ?Sized, A: Allocator> FnOnce<Args> for Box<F, A> {
type Output = <F as FnOnce<Args>>::Output;
extern "rust-call" fn call_once(self, args: Args) -> Self::Output {
<F as FnOnce<Args>>::call_once(*self, args)
}
}
#[stable(feature = "boxed_closure_impls", since = "1.35.0")]
impl<Args: Tuple, F: FnMut<Args> + ?Sized, A: Allocator> FnMut<Args> for Box<F, A> {
extern "rust-call" fn call_mut(&mut self, args: Args) -> Self::Output {
<F as FnMut<Args>>::call_mut(self, args)
}
}
#[stable(feature = "boxed_closure_impls", since = "1.35.0")]
impl<Args: Tuple, F: Fn<Args> + ?Sized, A: Allocator> Fn<Args> for Box<F, A> {
extern "rust-call" fn call(&self, args: Args) -> Self::Output {
<F as Fn<Args>>::call(self, args)
}
}
#[unstable(feature = "coerce_unsized", issue = "18598")]
impl<T: ?Sized + Unsize<U>, U: ?Sized, A: Allocator> CoerceUnsized<Box<U, A>> for Box<T, A> {}
#[unstable(feature = "dispatch_from_dyn", issue = "none")]
impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Box<U>> for Box<T, Global> {}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "boxed_slice_from_iter", since = "1.32.0")]
impl<I> FromIterator<I> for Box<[I]> {
fn from_iter<T: IntoIterator<Item = I>>(iter: T) -> Self {
iter.into_iter().collect::<Vec<_>>().into_boxed_slice()
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "box_slice_clone", since = "1.3.0")]
impl<T: Clone, A: Allocator + Clone> Clone for Box<[T], A> {
fn clone(&self) -> Self {
let alloc = Box::allocator(self).clone();
self.to_vec_in(alloc).into_boxed_slice()
}
fn clone_from(&mut self, other: &Self) {
if self.len() == other.len() {
self.clone_from_slice(&other);
} else {
*self = other.clone();
}
}
}
#[stable(feature = "box_borrow", since = "1.1.0")]
impl<T: ?Sized, A: Allocator> borrow::Borrow<T> for Box<T, A> {
fn borrow(&self) -> &T {
&**self
}
}
#[stable(feature = "box_borrow", since = "1.1.0")]
impl<T: ?Sized, A: Allocator> borrow::BorrowMut<T> for Box<T, A> {
fn borrow_mut(&mut self) -> &mut T {
&mut **self
}
}
#[stable(since = "1.5.0", feature = "smart_ptr_as_ref")]
impl<T: ?Sized, A: Allocator> AsRef<T> for Box<T, A> {
fn as_ref(&self) -> &T {
&**self
}
}
#[stable(since = "1.5.0", feature = "smart_ptr_as_ref")]
impl<T: ?Sized, A: Allocator> AsMut<T> for Box<T, A> {
fn as_mut(&mut self) -> &mut T {
&mut **self
}
}
/* Nota bene
*
* We could have chosen not to add this impl, and instead have written a
* function of Pin<Box<T>> to Pin<T>. Such a function would not be sound,
* because Box<T> implements Unpin even when T does not, as a result of
* this impl.
*
* We chose this API instead of the alternative for a few reasons:
* - Logically, it is helpful to understand pinning in regard to the
* memory region being pointed to. For this reason none of the
* standard library pointer types support projecting through a pin
* (Box<T> is the only pointer type in std for which this would be
* safe.)
* - It is in practice very useful to have Box<T> be unconditionally
* Unpin because of trait objects, for which the structural auto
* trait functionality does not apply (e.g., Box<dyn Foo> would
* otherwise not be Unpin).
*
* Another type with the same semantics as Box but only a conditional
* implementation of `Unpin` (where `T: Unpin`) would be valid/safe, and
* could have a method to project a Pin<T> from it.
*/
#[stable(feature = "pin", since = "1.33.0")]
impl<T: ?Sized, A: Allocator> Unpin for Box<T, A> where A: 'static {}
#[unstable(feature = "coroutine_trait", issue = "43122")]
impl<G: ?Sized + Coroutine<R> + Unpin, R, A: Allocator> Coroutine<R> for Box<G, A>
where
A: 'static,
{
type Yield = G::Yield;
type Return = G::Return;
fn resume(mut self: Pin<&mut Self>, arg: R) -> CoroutineState<Self::Yield, Self::Return> {
G::resume(Pin::new(&mut *self), arg)
}
}
#[unstable(feature = "coroutine_trait", issue = "43122")]
impl<G: ?Sized + Coroutine<R>, R, A: Allocator> Coroutine<R> for Pin<Box<G, A>>
where
A: 'static,
{
type Yield = G::Yield;
type Return = G::Return;
fn resume(mut self: Pin<&mut Self>, arg: R) -> CoroutineState<Self::Yield, Self::Return> {
G::resume((*self).as_mut(), arg)
}
}
#[stable(feature = "futures_api", since = "1.36.0")]
impl<F: ?Sized + Future + Unpin, A: Allocator> Future for Box<F, A>
where
A: 'static,
{
type Output = F::Output;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
F::poll(Pin::new(&mut *self), cx)
}
}
#[unstable(feature = "async_iterator", issue = "79024")]
impl<S: ?Sized + AsyncIterator + Unpin> AsyncIterator for Box<S> {
type Item = S::Item;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
Pin::new(&mut **self).poll_next(cx)
}
fn size_hint(&self) -> (usize, Option<usize>) {
(**self).size_hint()
}
}
impl dyn Error {
#[inline]
#[stable(feature = "error_downcast", since = "1.3.0")]
#[rustc_allow_incoherent_impl]
/// Attempts to downcast the box to a concrete type.
pub fn downcast<T: Error + 'static>(self: Box<Self>) -> Result<Box<T>, Box<dyn Error>> {
if self.is::<T>() {
unsafe {
let raw: *mut dyn Error = Box::into_raw(self);
Ok(Box::from_raw(raw as *mut T))
}
} else {
Err(self)
}
}
}
impl dyn Error + Send {
#[inline]
#[stable(feature = "error_downcast", since = "1.3.0")]
#[rustc_allow_incoherent_impl]
/// Attempts to downcast the box to a concrete type.
pub fn downcast<T: Error + 'static>(self: Box<Self>) -> Result<Box<T>, Box<dyn Error + Send>> {
let err: Box<dyn Error> = self;
<dyn Error>::downcast(err).map_err(|s| unsafe {
// Reapply the `Send` marker.
Box::from_raw(Box::into_raw(s) as *mut (dyn Error + Send))
})
}
}
impl dyn Error + Send + Sync {
#[inline]
#[stable(feature = "error_downcast", since = "1.3.0")]
#[rustc_allow_incoherent_impl]
/// Attempts to downcast the box to a concrete type.
pub fn downcast<T: Error + 'static>(self: Box<Self>) -> Result<Box<T>, Box<Self>> {
let err: Box<dyn Error> = self;
<dyn Error>::downcast(err).map_err(|s| unsafe {
// Reapply the `Send + Sync` marker.
Box::from_raw(Box::into_raw(s) as *mut (dyn Error + Send + Sync))
})
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, E: Error + 'a> From<E> for Box<dyn Error + 'a> {
/// Converts a type of [`Error`] into a box of dyn [`Error`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::fmt;
/// use std::mem;
///
/// #[derive(Debug)]
/// struct AnError;
///
/// impl fmt::Display for AnError {
/// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
/// write!(f, "An error")
/// }
/// }
///
/// impl Error for AnError {}
///
/// let an_error = AnError;
/// assert!(0 == mem::size_of_val(&an_error));
/// let a_boxed_error = Box::<dyn Error>::from(an_error);
/// assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: E) -> Box<dyn Error + 'a> {
Box::new(err)
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, E: Error + Send + Sync + 'a> From<E> for Box<dyn Error + Send + Sync + 'a> {
/// Converts a type of [`Error`] + [`Send`] + [`Sync`] into a box of
/// dyn [`Error`] + [`Send`] + [`Sync`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::fmt;
/// use std::mem;
///
/// #[derive(Debug)]
/// struct AnError;
///
/// impl fmt::Display for AnError {
/// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
/// write!(f, "An error")
/// }
/// }
///
/// impl Error for AnError {}
///
/// unsafe impl Send for AnError {}
///
/// unsafe impl Sync for AnError {}
///
/// let an_error = AnError;
/// assert!(0 == mem::size_of_val(&an_error));
/// let a_boxed_error = Box::<dyn Error + Send + Sync>::from(an_error);
/// assert!(
/// mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: E) -> Box<dyn Error + Send + Sync + 'a> {
Box::new(err)
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
impl From<String> for Box<dyn Error + Send + Sync> {
/// Converts a [`String`] into a box of dyn [`Error`] + [`Send`] + [`Sync`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
///
/// let a_string_error = "a string error".to_string();
/// let a_boxed_error = Box::<dyn Error + Send + Sync>::from(a_string_error);
/// assert!(
/// mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))
/// ```
#[inline]
fn from(err: String) -> Box<dyn Error + Send + Sync> {
struct StringError(String);
impl Error for StringError {
#[allow(deprecated)]
fn description(&self) -> &str {
&self.0
}
}
impl fmt::Display for StringError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&self.0, f)
}
}
// Purposefully skip printing "StringError(..)"
impl fmt::Debug for StringError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&self.0, f)
}
}
Box::new(StringError(err))
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "string_box_error", since = "1.6.0")]
impl From<String> for Box<dyn Error> {
/// Converts a [`String`] into a box of dyn [`Error`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
///
/// let a_string_error = "a string error".to_string();
/// let a_boxed_error = Box::<dyn Error>::from(a_string_error);
/// assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(str_err: String) -> Box<dyn Error> {
let err1: Box<dyn Error + Send + Sync> = From::from(str_err);
let err2: Box<dyn Error> = err1;
err2
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a> From<&str> for Box<dyn Error + Send + Sync + 'a> {
/// Converts a [`str`] into a box of dyn [`Error`] + [`Send`] + [`Sync`].
///
/// [`str`]: prim@str
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
///
/// let a_str_error = "a str error";
/// let a_boxed_error = Box::<dyn Error + Send + Sync>::from(a_str_error);
/// assert!(
/// mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))
/// ```
#[inline]
fn from(err: &str) -> Box<dyn Error + Send + Sync + 'a> {
From::from(String::from(err))
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "string_box_error", since = "1.6.0")]
impl From<&str> for Box<dyn Error> {
/// Converts a [`str`] into a box of dyn [`Error`].
///
/// [`str`]: prim@str
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
///
/// let a_str_error = "a str error";
/// let a_boxed_error = Box::<dyn Error>::from(a_str_error);
/// assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: &str) -> Box<dyn Error> {
From::from(String::from(err))
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "cow_box_error", since = "1.22.0")]
impl<'a, 'b> From<Cow<'b, str>> for Box<dyn Error + Send + Sync + 'a> {
/// Converts a [`Cow`] into a box of dyn [`Error`] + [`Send`] + [`Sync`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
/// use std::borrow::Cow;
///
/// let a_cow_str_error = Cow::from("a str error");
/// let a_boxed_error = Box::<dyn Error + Send + Sync>::from(a_cow_str_error);
/// assert!(
/// mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: Cow<'b, str>) -> Box<dyn Error + Send + Sync + 'a> {
From::from(String::from(err))
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "cow_box_error", since = "1.22.0")]
impl<'a> From<Cow<'a, str>> for Box<dyn Error> {
/// Converts a [`Cow`] into a box of dyn [`Error`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
/// use std::borrow::Cow;
///
/// let a_cow_str_error = Cow::from("a str error");
/// let a_boxed_error = Box::<dyn Error>::from(a_cow_str_error);
/// assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: Cow<'a, str>) -> Box<dyn Error> {
From::from(String::from(err))
}
}
#[stable(feature = "box_error", since = "1.8.0")]
impl<T: core::error::Error> core::error::Error for Box<T> {
#[allow(deprecated, deprecated_in_future)]
fn description(&self) -> &str {
core::error::Error::description(&**self)
}
#[allow(deprecated)]
fn cause(&self) -> Option<&dyn core::error::Error> {
core::error::Error::cause(&**self)
}
fn source(&self) -> Option<&(dyn core::error::Error + 'static)> {
core::error::Error::source(&**self)
}
fn provide<'b>(&'b self, request: &mut core::error::Request<'b>) {
core::error::Error::provide(&**self, request);
}
}
rust/alloc/collections/mod.rs deleted 100644 → 0
View file @ 84c7d76b
// SPDX-License-Identifier: Apache-2.0 OR MIT
//! Collection types.
#![stable(feature = "rust1", since = "1.0.0")]
#[cfg(not(no_global_oom_handling))]
pub mod binary_heap;
#[cfg(not(no_global_oom_handling))]
mod btree;
#[cfg(not(no_global_oom_handling))]
pub mod linked_list;
#[cfg(not(no_global_oom_handling))]
pub mod vec_deque;
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
pub mod btree_map {
//! An ordered map based on a B-Tree.
#[stable(feature = "rust1", since = "1.0.0")]
pub use super::btree::map::*;
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
pub mod btree_set {
//! An ordered set based on a B-Tree.
#[stable(feature = "rust1", since = "1.0.0")]
pub use super::btree::set::*;
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
#[doc(no_inline)]
pub use binary_heap::BinaryHeap;
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
#[doc(no_inline)]
pub use btree_map::BTreeMap;
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
#[doc(no_inline)]
pub use btree_set::BTreeSet;
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
#[doc(no_inline)]
pub use linked_list::LinkedList;
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
#[doc(no_inline)]
pub use vec_deque::VecDeque;
use crate::alloc::{Layout, LayoutError};
use core::fmt::Display;
/// The error type for `try_reserve` methods.
#[derive(Clone, PartialEq, Eq, Debug)]
#[stable(feature = "try_reserve", since = "1.57.0")]
pub struct TryReserveError {
kind: TryReserveErrorKind,
}
impl TryReserveError {
/// Details about the allocation that caused the error
#[inline]
#[must_use]
#[unstable(
feature = "try_reserve_kind",
reason = "Uncertain how much info should be exposed",
issue = "48043"
)]
pub fn kind(&self) -> TryReserveErrorKind {
self.kind.clone()
}
}
/// Details of the allocation that caused a `TryReserveError`
#[derive(Clone, PartialEq, Eq, Debug)]
#[unstable(
feature = "try_reserve_kind",
reason = "Uncertain how much info should be exposed",
issue = "48043"
)]
pub enum TryReserveErrorKind {
/// Error due to the computed capacity exceeding the collection's maximum
/// (usually `isize::MAX` bytes).
CapacityOverflow,
/// The memory allocator returned an error
AllocError {
/// The layout of allocation request that failed
layout: Layout,
#[doc(hidden)]
#[unstable(
feature = "container_error_extra",
issue = "none",
reason = "\
Enable exposing the allocator’s custom error value \
if an associated type is added in the future: \
https://github.com/rust-lang/wg-allocators/issues/23"
)]
non_exhaustive: (),
},
}
#[unstable(
feature = "try_reserve_kind",
reason = "Uncertain how much info should be exposed",
issue = "48043"
)]
impl From<TryReserveErrorKind> for TryReserveError {
#[inline]
fn from(kind: TryReserveErrorKind) -> Self {
Self { kind }
}
}
#[unstable(feature = "try_reserve_kind", reason = "new API", issue = "48043")]
impl From<LayoutError> for TryReserveErrorKind {
/// Always evaluates to [`TryReserveErrorKind::CapacityOverflow`].
#[inline]
fn from(_: LayoutError) -> Self {
TryReserveErrorKind::CapacityOverflow
}
}
#[stable(feature = "try_reserve", since = "1.57.0")]
impl Display for TryReserveError {
fn fmt(
&self,
fmt: &mut core::fmt::Formatter<'_>,
) -> core::result::Result<(), core::fmt::Error> {
fmt.write_str("memory allocation failed")?;
let reason = match self.kind {
TryReserveErrorKind::CapacityOverflow => {
" because the computed capacity exceeded the collection's maximum"
}
TryReserveErrorKind::AllocError { .. } => {
" because the memory allocator returned an error"
}
};
fmt.write_str(reason)
}
}
/// An intermediate trait for specialization of `Extend`.
#[doc(hidden)]
#[cfg(not(no_global_oom_handling))]
trait SpecExtend<I: IntoIterator> {
/// Extends `self` with the contents of the given iterator.
fn spec_extend(&mut self, iter: I);
}
#[stable(feature = "try_reserve", since = "1.57.0")]
impl core::error::Error for TryReserveError {}
rust/alloc/lib.rs deleted 100644 → 0
View file @ 84c7d76b
// SPDX-License-Identifier: Apache-2.0 OR MIT
//! # The Rust core allocation and collections library
//!
//! This library provides smart pointers and collections for managing
//! heap-allocated values.
//!
//! This library, like core, normally doesn’t need to be used directly
//! since its contents are re-exported in the [`std` crate](../std/index.html).
//! Crates that use the `#![no_std]` attribute however will typically
//! not depend on `std`, so they’d use this crate instead.
//!
//! ## Boxed values
//!
//! The [`Box`] type is a smart pointer type. There can only be one owner of a
//! [`Box`], and the owner can decide to mutate the contents, which live on the
//! heap.
//!
//! This type can be sent among threads efficiently as the size of a `Box` value
//! is the same as that of a pointer. Tree-like data structures are often built
//! with boxes because each node often has only one owner, the parent.
//!
//! ## Reference counted pointers
//!
//! The [`Rc`] type is a non-threadsafe reference-counted pointer type intended
//! for sharing memory within a thread. An [`Rc`] pointer wraps a type, `T`, and
//! only allows access to `&T`, a shared reference.
//!
//! This type is useful when inherited mutability (such as using [`Box`]) is too
//! constraining for an application, and is often paired with the [`Cell`] or
//! [`RefCell`] types in order to allow mutation.
//!
//! ## Atomically reference counted pointers
//!
//! The [`Arc`] type is the threadsafe equivalent of the [`Rc`] type. It
//! provides all the same functionality of [`Rc`], except it requires that the
//! contained type `T` is shareable. Additionally, [`Arc<T>`][`Arc`] is itself
//! sendable while [`Rc<T>`][`Rc`] is not.
//!
//! This type allows for shared access to the contained data, and is often
//! paired with synchronization primitives such as mutexes to allow mutation of
//! shared resources.
//!
//! ## Collections
//!
//! Implementations of the most common general purpose data structures are
//! defined in this library. They are re-exported through the
//! [standard collections library](../std/collections/index.html).
//!
//! ## Heap interfaces
//!
//! The [`alloc`](alloc/index.html) module defines the low-level interface to the
//! default global allocator. It is not compatible with the libc allocator API.
//!
//! [`Arc`]: sync
//! [`Box`]: boxed
//! [`Cell`]: core::cell
//! [`Rc`]: rc
//! [`RefCell`]: core::cell
// To run alloc tests without x.py without ending up with two copies of alloc, Miri needs to be
// able to "empty" this crate. See <https://github.com/rust-lang/miri-test-libstd/issues/4>.
// rustc itself never sets the feature, so this line has no effect there.
#![cfg(any(not(feature = "miri-test-libstd"), test, doctest))]
//
#![allow(unused_attributes)]
#![stable(feature = "alloc", since = "1.36.0")]
#![doc(
html_playground_url = "https://play.rust-lang.org/",
issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
test(no_crate_inject, attr(allow(unused_variables), deny(warnings)))
)]
#![doc(cfg_hide(
not(test),
not(any(test, bootstrap)),
any(not(feature = "miri-test-libstd"), test, doctest),
no_global_oom_handling,
not(no_global_oom_handling),
not(no_rc),
not(no_sync),
target_has_atomic = "ptr"
))]
#![doc(rust_logo)]
#![feature(rustdoc_internals)]
#![no_std]
#![needs_allocator]
// Lints:
#![deny(unsafe_op_in_unsafe_fn)]
#![deny(fuzzy_provenance_casts)]
#![warn(deprecated_in_future)]
#![warn(missing_debug_implementations)]
#![warn(missing_docs)]
#![allow(explicit_outlives_requirements)]
#![warn(multiple_supertrait_upcastable)]
#![allow(internal_features)]
#![allow(rustdoc::redundant_explicit_links)]
//
// Library features:
// tidy-alphabetical-start
#![cfg_attr(not(no_global_oom_handling), feature(const_alloc_error))]
#![cfg_attr(not(no_global_oom_handling), feature(const_btree_len))]
#![cfg_attr(test, feature(is_sorted))]
#![cfg_attr(test, feature(new_uninit))]
#![feature(alloc_layout_extra)]
#![feature(allocator_api)]
#![feature(array_chunks)]
#![feature(array_into_iter_constructors)]
#![feature(array_methods)]
#![feature(array_windows)]
#![feature(ascii_char)]
#![feature(assert_matches)]
#![feature(async_iterator)]
#![feature(coerce_unsized)]
#![feature(const_align_of_val)]
#![feature(const_box)]
#![cfg_attr(not(no_borrow), feature(const_cow_is_borrowed))]
#![feature(const_eval_select)]
#![feature(const_maybe_uninit_as_mut_ptr)]
#![feature(const_maybe_uninit_write)]
#![feature(const_pin)]
#![feature(const_refs_to_cell)]
#![feature(const_size_of_val)]
#![feature(const_waker)]
#![feature(core_intrinsics)]
#![feature(core_panic)]
#![feature(deprecated_suggestion)]
#![feature(dispatch_from_dyn)]
#![feature(error_generic_member_access)]
#![feature(error_in_core)]
#![feature(exact_size_is_empty)]
#![feature(extend_one)]
#![feature(fmt_internals)]
#![feature(fn_traits)]
#![feature(hasher_prefixfree_extras)]
#![feature(inline_const)]
#![feature(inplace_iteration)]
#![feature(iter_advance_by)]
#![feature(iter_next_chunk)]
#![feature(iter_repeat_n)]
#![feature(layout_for_ptr)]
#![feature(maybe_uninit_slice)]
#![feature(maybe_uninit_uninit_array)]
#![feature(maybe_uninit_uninit_array_transpose)]
#![feature(pattern)]
#![feature(ptr_internals)]
#![feature(ptr_metadata)]
#![feature(ptr_sub_ptr)]
#![feature(receiver_trait)]
#![feature(set_ptr_value)]
#![feature(sized_type_properties)]
#![feature(slice_from_ptr_range)]
#![feature(slice_group_by)]
#![feature(slice_ptr_get)]
#![feature(slice_ptr_len)]
#![feature(slice_range)]
#![feature(std_internals)]
#![feature(str_internals)]
#![feature(strict_provenance)]
#![feature(trusted_fused)]
#![feature(trusted_len)]
#![feature(trusted_random_access)]
#![feature(try_trait_v2)]
#![feature(tuple_trait)]
#![feature(unchecked_math)]
#![feature(unicode_internals)]
#![feature(unsize)]
#![feature(utf8_chunks)]
// tidy-alphabetical-end
//
// Language features:
// tidy-alphabetical-start
#![cfg_attr(not(test), feature(coroutine_trait))]
#![cfg_attr(test, feature(panic_update_hook))]
#![cfg_attr(test, feature(test))]
#![feature(allocator_internals)]
#![feature(allow_internal_unstable)]
#![feature(associated_type_bounds)]
#![feature(c_unwind)]
#![feature(cfg_sanitize)]
#![feature(const_mut_refs)]
#![feature(const_precise_live_drops)]
#![feature(const_ptr_write)]
#![feature(const_trait_impl)]
#![feature(const_try)]
#![feature(dropck_eyepatch)]
#![feature(exclusive_range_pattern)]
#![feature(fundamental)]
#![feature(hashmap_internals)]
#![feature(lang_items)]
#![feature(min_specialization)]
#![feature(multiple_supertrait_upcastable)]
#![feature(negative_impls)]
#![feature(never_type)]
#![feature(pointer_is_aligned)]
#![feature(rustc_allow_const_fn_unstable)]
#![feature(rustc_attrs)]
#![feature(slice_internals)]
#![feature(staged_api)]
#![feature(stmt_expr_attributes)]
#![feature(unboxed_closures)]
#![feature(unsized_fn_params)]
#![feature(with_negative_coherence)]
// tidy-alphabetical-end
//
// Rustdoc features:
#![feature(doc_cfg)]
#![feature(doc_cfg_hide)]
// Technically, this is a bug in rustdoc: rustdoc sees the documentation on `#[lang = slice_alloc]`
// blocks is for `&[T]`, which also has documentation using this feature in `core`, and gets mad
// that the feature-gate isn't enabled. Ideally, it wouldn't check for the feature gate for docs
// from other crates, but since this can only appear for lang items, it doesn't seem worth fixing.
#![feature(intra_doc_pointers)]
// Allow testing this library
#[cfg(test)]
#[macro_use]
extern crate std;
#[cfg(test)]
extern crate test;
#[cfg(test)]
mod testing;
// Module with internal macros used by other modules (needs to be included before other modules).
#[cfg(not(no_macros))]
#[macro_use]
mod macros;
mod raw_vec;
// Heaps provided for low-level allocation strategies
pub mod alloc;
// Primitive types using the heaps above
// Need to conditionally define the mod from `boxed.rs` to avoid
// duplicating the lang-items when building in test cfg; but also need
// to allow code to have `use boxed::Box;` declarations.
#[cfg(not(test))]
pub mod boxed;
#[cfg(test)]
mod boxed {
pub use std::boxed::Box;
}
#[cfg(not(no_borrow))]
pub mod borrow;
pub mod collections;
#[cfg(all(not(no_rc), not(no_sync), not(no_global_oom_handling)))]
pub mod ffi;
#[cfg(not(no_fmt))]
pub mod fmt;
#[cfg(not(no_rc))]
pub mod rc;
pub mod slice;
#[cfg(not(no_str))]
pub mod str;
#[cfg(not(no_string))]
pub mod string;
#[cfg(all(not(no_rc), not(no_sync), target_has_atomic = "ptr"))]
pub mod sync;
#[cfg(all(not(no_global_oom_handling), not(no_rc), not(no_sync), target_has_atomic = "ptr"))]
pub mod task;
#[cfg(test)]
mod tests;
pub mod vec;
#[doc(hidden)]
#[unstable(feature = "liballoc_internals", issue = "none", reason = "implementation detail")]
pub mod __export {
pub use core::format_args;
}
#[cfg(test)]
#[allow(dead_code)] // Not used in all configurations
pub(crate) mod test_helpers {
/// Copied from `std::test_helpers::test_rng`, since these tests rely on the
/// seed not being the same for every RNG invocation too.
pub(crate) fn test_rng() -> rand_xorshift::XorShiftRng {
use std::hash::{BuildHasher, Hash, Hasher};
let mut hasher = std::hash::RandomState::new().build_hasher();
std::panic::Location::caller().hash(&mut hasher);
let hc64 = hasher.finish();
let seed_vec =
hc64.to_le_bytes().into_iter().chain(0u8..8).collect::<crate::vec::Vec<u8>>();
let seed: [u8; 16] = seed_vec.as_slice().try_into().unwrap();
rand::SeedableRng::from_seed(seed)
}
}
rust/alloc/raw_vec.rs deleted 100644 → 0
View file @ 84c7d76b
// SPDX-License-Identifier: Apache-2.0 OR MIT
#![unstable(feature = "raw_vec_internals", reason = "unstable const warnings", issue = "none")]
use core::alloc::LayoutError;
use core::cmp;
use core::intrinsics;
use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties};
use core::ptr::{self, NonNull, Unique};
use core::slice;
#[cfg(not(no_global_oom_handling))]
use crate::alloc::handle_alloc_error;
use crate::alloc::{Allocator, Global, Layout};
use crate::boxed::Box;
use crate::collections::TryReserveError;
use crate::collections::TryReserveErrorKind::*;
#[cfg(test)]
mod tests;
enum AllocInit {
/// The contents of the new memory are uninitialized.
Uninitialized,
/// The new memory is guaranteed to be zeroed.
#[allow(dead_code)]
Zeroed,
}
#[repr(transparent)]
#[cfg_attr(target_pointer_width = "16", rustc_layout_scalar_valid_range_end(0x7fff))]
#[cfg_attr(target_pointer_width = "32", rustc_layout_scalar_valid_range_end(0x7fff_ffff))]
#[cfg_attr(target_pointer_width = "64", rustc_layout_scalar_valid_range_end(0x7fff_ffff_ffff_ffff))]
struct Cap(usize);
impl Cap {
const ZERO: Cap = unsafe { Cap(0) };
}
/// A low-level utility for more ergonomically allocating, reallocating, and deallocating
/// a buffer of memory on the heap without having to worry about all the corner cases
/// involved. This type is excellent for building your own data structures like Vec and VecDeque.
/// In particular:
///
/// * Produces `Unique::dangling()` on zero-sized types.
/// * Produces `Unique::dangling()` on zero-length allocations.
/// * Avoids freeing `Unique::dangling()`.
/// * Catches all overflows in capacity computations (promotes them to "capacity overflow" panics).
/// * Guards against 32-bit systems allocating more than isize::MAX bytes.
/// * Guards against overflowing your length.
/// * Calls `handle_alloc_error` for fallible allocations.
/// * Contains a `ptr::Unique` and thus endows the user with all related benefits.
/// * Uses the excess returned from the allocator to use the largest available capacity.
///
/// This type does not in anyway inspect the memory that it manages. When dropped it *will*
/// free its memory, but it *won't* try to drop its contents. It is up to the user of `RawVec`
/// to handle the actual things *stored* inside of a `RawVec`.
///
/// Note that the excess of a zero-sized types is always infinite, so `capacity()` always returns
/// `usize::MAX`. This means that you need to be careful when round-tripping this type with a
/// `Box<[T]>`, since `capacity()` won't yield the length.
#[allow(missing_debug_implementations)]
pub(crate) struct RawVec<T, A: Allocator = Global> {
ptr: Unique<T>,
/// Never used for ZSTs; it's `capacity()`'s responsibility to return usize::MAX in that case.
///
/// # Safety
///
/// `cap` must be in the `0..=isize::MAX` range.
cap: Cap,
alloc: A,
}
impl<T> RawVec<T, Global> {
/// HACK(Centril): This exists because stable `const fn` can only call stable `const fn`, so
/// they cannot call `Self::new()`.
///
/// If you change `RawVec<T>::new` or dependencies, please take care to not introduce anything
/// that would truly const-call something unstable.
pub const NEW: Self = Self::new();
/// Creates the biggest possible `RawVec` (on the system heap)
/// without allocating. If `T` has positive size, then this makes a
/// `RawVec` with capacity `0`. If `T` is zero-sized, then it makes a
/// `RawVec` with capacity `usize::MAX`. Useful for implementing
/// delayed allocation.
#[must_use]
pub const fn new() -> Self {
Self::new_in(Global)
}
/// Creates a `RawVec` (on the system heap) with exactly the
/// capacity and alignment requirements for a `[T; capacity]`. This is
/// equivalent to calling `RawVec::new` when `capacity` is `0` or `T` is
/// zero-sized. Note that if `T` is zero-sized this means you will
/// *not* get a `RawVec` with the requested capacity.
///
/// # Panics
///
/// Panics if the requested capacity exceeds `isize::MAX` bytes.
///
/// # Aborts
///
/// Aborts on OOM.
#[cfg(not(any(no_global_oom_handling, test)))]
#[must_use]
#[inline]
pub fn with_capacity(capacity: usize) -> Self {
Self::with_capacity_in(capacity, Global)
}
/// Like `with_capacity`, but guarantees the buffer is zeroed.
#[cfg(not(any(no_global_oom_handling, test)))]
#[must_use]
#[inline]
pub fn with_capacity_zeroed(capacity: usize) -> Self {
Self::with_capacity_zeroed_in(capacity, Global)
}
}
impl<T, A: Allocator> RawVec<T, A> {
// Tiny Vecs are dumb. Skip to:
// - 8 if the element size is 1, because any heap allocators is likely
// to round up a request of less than 8 bytes to at least 8 bytes.
// - 4 if elements are moderate-sized (<= 1 KiB).
// - 1 otherwise, to avoid wasting too much space for very short Vecs.
pub(crate) const MIN_NON_ZERO_CAP: usize = if mem::size_of::<T>() == 1 {
8
} else if mem::size_of::<T>() <= 1024 {
4
} else {
1
};
/// Like `new`, but parameterized over the choice of allocator for
/// the returned `RawVec`.
pub const fn new_in(alloc: A) -> Self {
// `cap: 0` means "unallocated". zero-sized types are ignored.
Self { ptr: Unique::dangling(), cap: Cap::ZERO, alloc }
}
/// Like `with_capacity`, but parameterized over the choice of
/// allocator for the returned `RawVec`.
#[cfg(not(no_global_oom_handling))]
#[inline]
pub fn with_capacity_in(capacity: usize, alloc: A) -> Self {
Self::allocate_in(capacity, AllocInit::Uninitialized, alloc)
}
/// Like `try_with_capacity`, but parameterized over the choice of
/// allocator for the returned `RawVec`.
#[inline]
pub fn try_with_capacity_in(capacity: usize, alloc: A) -> Result<Self, TryReserveError> {
Self::try_allocate_in(capacity, AllocInit::Uninitialized, alloc)
}
/// Like `with_capacity_zeroed`, but parameterized over the choice
/// of allocator for the returned `RawVec`.
#[cfg(not(no_global_oom_handling))]
#[inline]
pub fn with_capacity_zeroed_in(capacity: usize, alloc: A) -> Self {
Self::allocate_in(capacity, AllocInit::Zeroed, alloc)
}
/// Converts the entire buffer into `Box<[MaybeUninit<T>]>` with the specified `len`.
///
/// Note that this will correctly reconstitute any `cap` changes
/// that may have been performed. (See description of type for details.)
///
/// # Safety
///
/// * `len` must be greater than or equal to the most recently requested capacity, and
/// * `len` must be less than or equal to `self.capacity()`.
///
/// Note, that the requested capacity and `self.capacity()` could differ, as
/// an allocator could overallocate and return a greater memory block than requested.
pub unsafe fn into_box(self, len: usize) -> Box<[MaybeUninit<T>], A> {
// Sanity-check one half of the safety requirement (we cannot check the other half).
debug_assert!(
len <= self.capacity(),
"`len` must be smaller than or equal to `self.capacity()`"
);
let me = ManuallyDrop::new(self);
unsafe {
let slice = slice::from_raw_parts_mut(me.ptr() as *mut MaybeUninit<T>, len);
Box::from_raw_in(slice, ptr::read(&me.alloc))
}
}
#[cfg(not(no_global_oom_handling))]
fn allocate_in(capacity: usize, init: AllocInit, alloc: A) -> Self {
// Don't allocate here because `Drop` will not deallocate when `capacity` is 0.
if T::IS_ZST || capacity == 0 {
Self::new_in(alloc)
} else {
// We avoid `unwrap_or_else` here because it bloats the amount of
// LLVM IR generated.
let layout = match Layout::array::<T>(capacity) {
Ok(layout) => layout,
Err(_) => capacity_overflow(),
};
match alloc_guard(layout.size()) {
Ok(_) => {}
Err(_) => capacity_overflow(),
}
let result = match init {
AllocInit::Uninitialized => alloc.allocate(layout),
AllocInit::Zeroed => alloc.allocate_zeroed(layout),
};
let ptr = match result {
Ok(ptr) => ptr,
Err(_) => handle_alloc_error(layout),
};
// Allocators currently return a `NonNull<[u8]>` whose length
// matches the size requested. If that ever changes, the capacity
// here should change to `ptr.len() / mem::size_of::<T>()`.
Self {
ptr: unsafe { Unique::new_unchecked(ptr.cast().as_ptr()) },
cap: unsafe { Cap(capacity) },
alloc,
}
}
}
fn try_allocate_in(capacity: usize, init: AllocInit, alloc: A) -> Result<Self, TryReserveError> {
// Don't allocate here because `Drop` will not deallocate when `capacity` is 0.
if T::IS_ZST || capacity == 0 {
return Ok(Self::new_in(alloc));
}
let layout = Layout::array::<T>(capacity).map_err(|_| CapacityOverflow)?;
alloc_guard(layout.size())?;
let result = match init {
AllocInit::Uninitialized => alloc.allocate(layout),
AllocInit::Zeroed => alloc.allocate_zeroed(layout),
};
let ptr = result.map_err(|_| AllocError { layout, non_exhaustive: () })?;
// Allocators currently return a `NonNull<[u8]>` whose length
// matches the size requested. If that ever changes, the capacity
// here should change to `ptr.len() / mem::size_of::<T>()`.
Ok(Self {
ptr: unsafe { Unique::new_unchecked(ptr.cast().as_ptr()) },
cap: unsafe { Cap(capacity) },
alloc,
})
}
/// Reconstitutes a `RawVec` from a pointer, capacity, and allocator.
///
/// # Safety
///
/// The `ptr` must be allocated (via the given allocator `alloc`), and with the given
/// `capacity`.
/// The `capacity` cannot exceed `isize::MAX` for sized types. (only a concern on 32-bit
/// systems). For ZSTs capacity is ignored.
/// If the `ptr` and `capacity` come from a `RawVec` created via `alloc`, then this is
/// guaranteed.
#[inline]
pub unsafe fn from_raw_parts_in(ptr: *mut T, capacity: usize, alloc: A) -> Self {
let cap = if T::IS_ZST { Cap::ZERO } else { unsafe { Cap(capacity) } };
Self { ptr: unsafe { Unique::new_unchecked(ptr) }, cap, alloc }
}
/// Gets a raw pointer to the start of the allocation. Note that this is
/// `Unique::dangling()` if `capacity == 0` or `T` is zero-sized. In the former case, you must
/// be careful.
#[inline]
pub fn ptr(&self) -> *mut T {
self.ptr.as_ptr()
}
/// Gets the capacity of the allocation.
///
/// This will always be `usize::MAX` if `T` is zero-sized.
#[inline(always)]
pub fn capacity(&self) -> usize {
if T::IS_ZST { usize::MAX } else { self.cap.0 }
}
/// Returns a shared reference to the allocator backing this `RawVec`.
pub fn allocator(&self) -> &A {
&self.alloc
}
fn current_memory(&self) -> Option<(NonNull<u8>, Layout)> {
if T::IS_ZST || self.cap.0 == 0 {
None
} else {
// We could use Layout::array here which ensures the absence of isize and usize overflows
// and could hypothetically handle differences between stride and size, but this memory
// has already been allocated so we know it can't overflow and currently rust does not
// support such types. So we can do better by skipping some checks and avoid an unwrap.
let _: () = const { assert!(mem::size_of::<T>() % mem::align_of::<T>() == 0) };
unsafe {
let align = mem::align_of::<T>();
let size = mem::size_of::<T>().unchecked_mul(self.cap.0);
let layout = Layout::from_size_align_unchecked(size, align);
Some((self.ptr.cast().into(), layout))
}
}
}
/// Ensures that the buffer contains at least enough space to hold `len +
/// additional` elements. If it doesn't already have enough capacity, will
/// reallocate enough space plus comfortable slack space to get amortized
/// *O*(1) behavior. Will limit this behavior if it would needlessly cause
/// itself to panic.
///
/// If `len` exceeds `self.capacity()`, this may fail to actually allocate
/// the requested space. This is not really unsafe, but the unsafe
/// code *you* write that relies on the behavior of this function may break.
///
/// This is ideal for implementing a bulk-push operation like `extend`.
///
/// # Panics
///
/// Panics if the new capacity exceeds `isize::MAX` bytes.
///
/// # Aborts
///
/// Aborts on OOM.
#[cfg(not(no_global_oom_handling))]
#[inline]
pub fn reserve(&mut self, len: usize, additional: usize) {
// Callers expect this function to be very cheap when there is already sufficient capacity.
// Therefore, we move all the resizing and error-handling logic from grow_amortized and
// handle_reserve behind a call, while making sure that this function is likely to be
// inlined as just a comparison and a call if the comparison fails.
#[cold]
fn do_reserve_and_handle<T, A: Allocator>(
slf: &mut RawVec<T, A>,
len: usize,
additional: usize,
) {
handle_reserve(slf.grow_amortized(len, additional));
}
if self.needs_to_grow(len, additional) {
do_reserve_and_handle(self, len, additional);
}
}
/// A specialized version of `reserve()` used only by the hot and
/// oft-instantiated `Vec::push()`, which does its own capacity check.
#[cfg(not(no_global_oom_handling))]
#[inline(never)]
pub fn reserve_for_push(&mut self, len: usize) {
handle_reserve(self.grow_amortized(len, 1));
}
/// The same as `reserve`, but returns on errors instead of panicking or aborting.
pub fn try_reserve(&mut self, len: usize, additional: usize) -> Result<(), TryReserveError> {
if self.needs_to_grow(len, additional) {
self.grow_amortized(len, additional)?;
}
unsafe {
// Inform the optimizer that the reservation has succeeded or wasn't needed
core::intrinsics::assume(!self.needs_to_grow(len, additional));
}
Ok(())
}
/// The same as `reserve_for_push`, but returns on errors instead of panicking or aborting.
#[inline(never)]
pub fn try_reserve_for_push(&mut self, len: usize) -> Result<(), TryReserveError> {
self.grow_amortized(len, 1)
}
/// Ensures that the buffer contains at least enough space to hold `len +
/// additional` elements. If it doesn't already, will reallocate the
/// minimum possible amount of memory necessary. Generally this will be
/// exactly the amount of memory necessary, but in principle the allocator
/// is free to give back more than we asked for.
///
/// If `len` exceeds `self.capacity()`, this may fail to actually allocate
/// the requested space. This is not really unsafe, but the unsafe code
/// *you* write that relies on the behavior of this function may break.
///
/// # Panics
///
/// Panics if the new capacity exceeds `isize::MAX` bytes.
///
/// # Aborts
///
/// Aborts on OOM.
#[cfg(not(no_global_oom_handling))]
pub fn reserve_exact(&mut self, len: usize, additional: usize) {
handle_reserve(self.try_reserve_exact(len, additional));
}
/// The same as `reserve_exact`, but returns on errors instead of panicking or aborting.
pub fn try_reserve_exact(
&mut self,
len: usize,
additional: usize,
) -> Result<(), TryReserveError> {
if self.needs_to_grow(len, additional) {
self.grow_exact(len, additional)?;
}
unsafe {
// Inform the optimizer that the reservation has succeeded or wasn't needed
core::intrinsics::assume(!self.needs_to_grow(len, additional));
}
Ok(())
}
/// Shrinks the buffer down to the specified capacity. If the given amount
/// is 0, actually completely deallocates.
///
/// # Panics
///
/// Panics if the given amount is *larger* than the current capacity.
///
/// # Aborts
///
/// Aborts on OOM.
#[cfg(not(no_global_oom_handling))]
pub fn shrink_to_fit(&mut self, cap: usize) {
handle_reserve(self.shrink(cap));
}
}
impl<T, A: Allocator> RawVec<T, A> {
/// Returns if the buffer needs to grow to fulfill the needed extra capacity.
/// Mainly used to make inlining reserve-calls possible without inlining `grow`.
fn needs_to_grow(&self, len: usize, additional: usize) -> bool {
additional > self.capacity().wrapping_sub(len)
}
/// # Safety:
///
/// `cap` must not exceed `isize::MAX`.
unsafe fn set_ptr_and_cap(&mut self, ptr: NonNull<[u8]>, cap: usize) {
// Allocators currently return a `NonNull<[u8]>` whose length matches
// the size requested. If that ever changes, the capacity here should
// change to `ptr.len() / mem::size_of::<T>()`.
self.ptr = unsafe { Unique::new_unchecked(ptr.cast().as_ptr()) };
self.cap = unsafe { Cap(cap) };
}
// This method is usually instantiated many times. So we want it to be as
// small as possible, to improve compile times. But we also want as much of
// its contents to be statically computable as possible, to make the
// generated code run faster. Therefore, this method is carefully written
// so that all of the code that depends on `T` is within it, while as much
// of the code that doesn't depend on `T` as possible is in functions that
// are non-generic over `T`.
fn grow_amortized(&mut self, len: usize, additional: usize) -> Result<(), TryReserveError> {
// This is ensured by the calling contexts.
debug_assert!(additional > 0);
if T::IS_ZST {
// Since we return a capacity of `usize::MAX` when `elem_size` is
// 0, getting to here necessarily means the `RawVec` is overfull.
return Err(CapacityOverflow.into());
}
// Nothing we can really do about these checks, sadly.
let required_cap = len.checked_add(additional).ok_or(CapacityOverflow)?;
// This guarantees exponential growth. The doubling cannot overflow
// because `cap <= isize::MAX` and the type of `cap` is `usize`.
let cap = cmp::max(self.cap.0 * 2, required_cap);
let cap = cmp::max(Self::MIN_NON_ZERO_CAP, cap);
let new_layout = Layout::array::<T>(cap);
// `finish_grow` is non-generic over `T`.
let ptr = finish_grow(new_layout, self.current_memory(), &mut self.alloc)?;
// SAFETY: finish_grow would have resulted in a capacity overflow if we tried to allocate more than isize::MAX items
unsafe { self.set_ptr_and_cap(ptr, cap) };
Ok(())
}
// The constraints on this method are much the same as those on
// `grow_amortized`, but this method is usually instantiated less often so
// it's less critical.
fn grow_exact(&mut self, len: usize, additional: usize) -> Result<(), TryReserveError> {
if T::IS_ZST {
// Since we return a capacity of `usize::MAX` when the type size is
// 0, getting to here necessarily means the `RawVec` is overfull.
return Err(CapacityOverflow.into());
}
let cap = len.checked_add(additional).ok_or(CapacityOverflow)?;
let new_layout = Layout::array::<T>(cap);
// `finish_grow` is non-generic over `T`.
let ptr = finish_grow(new_layout, self.current_memory(), &mut self.alloc)?;
// SAFETY: finish_grow would have resulted in a capacity overflow if we tried to allocate more than isize::MAX items
unsafe {
self.set_ptr_and_cap(ptr, cap);
}
Ok(())
}
#[cfg(not(no_global_oom_handling))]
fn shrink(&mut self, cap: usize) -> Result<(), TryReserveError> {
assert!(cap <= self.capacity(), "Tried to shrink to a larger capacity");
let (ptr, layout) = if let Some(mem) = self.current_memory() { mem } else { return Ok(()) };
// See current_memory() why this assert is here
let _: () = const { assert!(mem::size_of::<T>() % mem::align_of::<T>() == 0) };
// If shrinking to 0, deallocate the buffer. We don't reach this point
// for the T::IS_ZST case since current_memory() will have returned
// None.
if cap == 0 {
unsafe { self.alloc.deallocate(ptr, layout) };
self.ptr = Unique::dangling();
self.cap = Cap::ZERO;
} else {
let ptr = unsafe {
// `Layout::array` cannot overflow here because it would have
// overflowed earlier when capacity was larger.
let new_size = mem::size_of::<T>().unchecked_mul(cap);
let new_layout = Layout::from_size_align_unchecked(new_size, layout.align());
self.alloc
.shrink(ptr, layout, new_layout)
.map_err(|_| AllocError { layout: new_layout, non_exhaustive: () })?
};
// SAFETY: if the allocation is valid, then the capacity is too
unsafe {
self.set_ptr_and_cap(ptr, cap);
}
}
Ok(())
}
}
// This function is outside `RawVec` to minimize compile times. See the comment
// above `RawVec::grow_amortized` for details. (The `A` parameter isn't
// significant, because the number of different `A` types seen in practice is
// much smaller than the number of `T` types.)
#[inline(never)]
fn finish_grow<A>(
new_layout: Result<Layout, LayoutError>,
current_memory: Option<(NonNull<u8>, Layout)>,
alloc: &mut A,
) -> Result<NonNull<[u8]>, TryReserveError>
where
A: Allocator,
{
// Check for the error here to minimize the size of `RawVec::grow_*`.
let new_layout = new_layout.map_err(|_| CapacityOverflow)?;
alloc_guard(new_layout.size())?;
let memory = if let Some((ptr, old_layout)) = current_memory {
debug_assert_eq!(old_layout.align(), new_layout.align());
unsafe {
// The allocator checks for alignment equality
intrinsics::assume(old_layout.align() == new_layout.align());
alloc.grow(ptr, old_layout, new_layout)
}
} else {
alloc.allocate(new_layout)
};
memory.map_err(|_| AllocError { layout: new_layout, non_exhaustive: () }.into())
}
unsafe impl<#[may_dangle] T, A: Allocator> Drop for RawVec<T, A> {
/// Frees the memory owned by the `RawVec` *without* trying to drop its contents.
fn drop(&mut self) {
if let Some((ptr, layout)) = self.current_memory() {
unsafe { self.alloc.deallocate(ptr, layout) }
}
}
}
// Central function for reserve error handling.
#[cfg(not(no_global_oom_handling))]
#[inline]
fn handle_reserve(result: Result<(), TryReserveError>) {
match result.map_err(|e| e.kind()) {
Err(CapacityOverflow) => capacity_overflow(),
Err(AllocError { layout, .. }) => handle_alloc_error(layout),
Ok(()) => { /* yay */ }
}
}
// We need to guarantee the following:
// * We don't ever allocate `> isize::MAX` byte-size objects.
// * We don't overflow `usize::MAX` and actually allocate too little.
//
// On 64-bit we just need to check for overflow since trying to allocate
// `> isize::MAX` bytes will surely fail. On 32-bit and 16-bit we need to add
// an extra guard for this in case we're running on a platform which can use
// all 4GB in user-space, e.g., PAE or x32.
#[inline]
fn alloc_guard(alloc_size: usize) -> Result<(), TryReserveError> {
if usize::BITS < 64 && alloc_size > isize::MAX as usize {
Err(CapacityOverflow.into())
} else {
Ok(())
}
}
// One central function responsible for reporting capacity overflows. This'll
// ensure that the code generation related to these panics is minimal as there's
// only one location which panics rather than a bunch throughout the module.
#[cfg(not(no_global_oom_handling))]
#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
fn capacity_overflow() -> ! {
panic!("capacity overflow");
}
rust/alloc/slice.rs deleted 100644 → 0
View file @ 84c7d76b
// SPDX-License-Identifier: Apache-2.0 OR MIT
//! Utilities for the slice primitive type.
//!
//! *[See also the slice primitive type](slice).*
//!
//! Most of the structs in this module are iterator types which can only be created
//! using a certain function. For example, `slice.iter()` yields an [`Iter`].
//!
//! A few functions are provided to create a slice from a value reference
//! or from a raw pointer.
#![stable(feature = "rust1", since = "1.0.0")]
// Many of the usings in this module are only used in the test configuration.
// It's cleaner to just turn off the unused_imports warning than to fix them.
#![cfg_attr(test, allow(unused_imports, dead_code))]
use core::borrow::{Borrow, BorrowMut};
#[cfg(not(no_global_oom_handling))]
use core::cmp::Ordering::{self, Less};
#[cfg(not(no_global_oom_handling))]
use core::mem::{self, SizedTypeProperties};
#[cfg(not(no_global_oom_handling))]
use core::ptr;
#[cfg(not(no_global_oom_handling))]
use core::slice::sort;
use crate::alloc::Allocator;
#[cfg(not(no_global_oom_handling))]
use crate::alloc::{self, Global};
#[cfg(not(no_global_oom_handling))]
use crate::borrow::ToOwned;
use crate::boxed::Box;
use crate::vec::Vec;
#[cfg(test)]
mod tests;
#[unstable(feature = "slice_range", issue = "76393")]
pub use core::slice::range;
#[unstable(feature = "array_chunks", issue = "74985")]
pub use core::slice::ArrayChunks;
#[unstable(feature = "array_chunks", issue = "74985")]
pub use core::slice::ArrayChunksMut;
#[unstable(feature = "array_windows", issue = "75027")]
pub use core::slice::ArrayWindows;
#[stable(feature = "inherent_ascii_escape", since = "1.60.0")]
pub use core::slice::EscapeAscii;
#[stable(feature = "slice_get_slice", since = "1.28.0")]
pub use core::slice::SliceIndex;
#[stable(feature = "from_ref", since = "1.28.0")]
pub use core::slice::{from_mut, from_ref};
#[unstable(feature = "slice_from_ptr_range", issue = "89792")]
pub use core::slice::{from_mut_ptr_range, from_ptr_range};
#[stable(feature = "rust1", since = "1.0.0")]
pub use core::slice::{from_raw_parts, from_raw_parts_mut};
#[stable(feature = "rust1", since = "1.0.0")]
pub use core::slice::{Chunks, Windows};
#[stable(feature = "chunks_exact", since = "1.31.0")]
pub use core::slice::{ChunksExact, ChunksExactMut};
#[stable(feature = "rust1", since = "1.0.0")]
pub use core::slice::{ChunksMut, Split, SplitMut};
#[unstable(feature = "slice_group_by", issue = "80552")]
pub use core::slice::{GroupBy, GroupByMut};
#[stable(feature = "rust1", since = "1.0.0")]
pub use core::slice::{Iter, IterMut};
#[stable(feature = "rchunks", since = "1.31.0")]
pub use core::slice::{RChunks, RChunksExact, RChunksExactMut, RChunksMut};
#[stable(feature = "slice_rsplit", since = "1.27.0")]
pub use core::slice::{RSplit, RSplitMut};
#[stable(feature = "rust1", since = "1.0.0")]
pub use core::slice::{RSplitN, RSplitNMut, SplitN, SplitNMut};
#[stable(feature = "split_inclusive", since = "1.51.0")]
pub use core::slice::{SplitInclusive, SplitInclusiveMut};
////////////////////////////////////////////////////////////////////////////////
// Basic slice extension methods
////////////////////////////////////////////////////////////////////////////////
// HACK(japaric) needed for the implementation of `vec!` macro during testing
// N.B., see the `hack` module in this file for more details.
#[cfg(test)]
pub use hack::into_vec;
// HACK(japaric) needed for the implementation of `Vec::clone` during testing
// N.B., see the `hack` module in this file for more details.
#[cfg(test)]
pub use hack::to_vec;
// HACK(japaric): With cfg(test) `impl [T]` is not available, these three
// functions are actually methods that are in `impl [T]` but not in
// `core::slice::SliceExt` - we need to supply these functions for the
// `test_permutations` test
pub(crate) mod hack {
use core::alloc::Allocator;
use crate::boxed::Box;
use crate::vec::Vec;
// We shouldn't add inline attribute to this since this is used in
// `vec!` macro mostly and causes perf regression. See #71204 for
// discussion and perf results.
pub fn into_vec<T, A: Allocator>(b: Box<[T], A>) -> Vec<T, A> {
unsafe {
let len = b.len();
let (b, alloc) = Box::into_raw_with_allocator(b);
Vec::from_raw_parts_in(b as *mut T, len, len, alloc)
}
}
#[cfg(not(no_global_oom_handling))]
#[inline]
pub fn to_vec<T: ConvertVec, A: Allocator>(s: &[T], alloc: A) -> Vec<T, A> {
T::to_vec(s, alloc)
}
#[cfg(not(no_global_oom_handling))]
pub trait ConvertVec {
fn to_vec<A: Allocator>(s: &[Self], alloc: A) -> Vec<Self, A>
where
Self: Sized;
}
#[cfg(not(no_global_oom_handling))]
impl<T: Clone> ConvertVec for T {
#[inline]
default fn to_vec<A: Allocator>(s: &[Self], alloc: A) -> Vec<Self, A> {
struct DropGuard<'a, T, A: Allocator> {
vec: &'a mut Vec<T, A>,
num_init: usize,
}
impl<'a, T, A: Allocator> Drop for DropGuard<'a, T, A> {
#[inline]
fn drop(&mut self) {
// SAFETY:
// items were marked initialized in the loop below
unsafe {
self.vec.set_len(self.num_init);
}
}
}
let mut vec = Vec::with_capacity_in(s.len(), alloc);
let mut guard = DropGuard { vec: &mut vec, num_init: 0 };
let slots = guard.vec.spare_capacity_mut();
// .take(slots.len()) is necessary for LLVM to remove bounds checks
// and has better codegen than zip.
for (i, b) in s.iter().enumerate().take(slots.len()) {
guard.num_init = i;
slots[i].write(b.clone());
}
core::mem::forget(guard);
// SAFETY:
// the vec was allocated and initialized above to at least this length.
unsafe {
vec.set_len(s.len());
}
vec
}
}
#[cfg(not(no_global_oom_handling))]
impl<T: Copy> ConvertVec for T {
#[inline]
fn to_vec<A: Allocator>(s: &[Self], alloc: A) -> Vec<Self, A> {
let mut v = Vec::with_capacity_in(s.len(), alloc);
// SAFETY:
// allocated above with the capacity of `s`, and initialize to `s.len()` in
// ptr::copy_to_non_overlapping below.
unsafe {
s.as_ptr().copy_to_nonoverlapping(v.as_mut_ptr(), s.len());
v.set_len(s.len());
}
v
}
}
}
#[cfg(not(test))]
impl<T> [T] {
/// Sorts the slice.
///
/// This sort is stable (i.e., does not reorder equal elements) and *O*(*n* \* log(*n*)) worst-case.
///
/// When applicable, unstable sorting is preferred because it is generally faster than stable
/// sorting and it doesn't allocate auxiliary memory.
/// See [`sort_unstable`](slice::sort_unstable).
///
/// # Current implementation
///
/// The current algorithm is an adaptive, iterative merge sort inspired by
/// [timsort](https://en.wikipedia.org/wiki/Timsort).
/// It is designed to be very fast in cases where the slice is nearly sorted, or consists of
/// two or more sorted sequences concatenated one after another.
///
/// Also, it allocates temporary storage half the size of `self`, but for short slices a
/// non-allocating insertion sort is used instead.
///
/// # Examples
///
/// ```
/// let mut v = [-5, 4, 1, -3, 2];
///
/// v.sort();
/// assert!(v == [-5, -3, 1, 2, 4]);
/// ```
#[cfg(not(no_global_oom_handling))]
#[rustc_allow_incoherent_impl]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn sort(&mut self)
where
T: Ord,
{
stable_sort(self, T::lt);
}
/// Sorts the slice with a comparator function.
///
/// This sort is stable (i.e., does not reorder equal elements) and *O*(*n* \* log(*n*)) worst-case.
///
/// The comparator function must define a total ordering for the elements in the slice. If
/// the ordering is not total, the order of the elements is unspecified. An order is a
/// total order if it is (for all `a`, `b` and `c`):
///
/// * total and antisymmetric: exactly one of `a < b`, `a == b` or `a > b` is true, and
/// * transitive, `a < b` and `b < c` implies `a < c`. The same must hold for both `==` and `>`.
///
/// For example, while [`f64`] doesn't implement [`Ord`] because `NaN != NaN`, we can use
/// `partial_cmp` as our sort function when we know the slice doesn't contain a `NaN`.
///
/// ```
/// let mut floats = [5f64, 4.0, 1.0, 3.0, 2.0];
/// floats.sort_by(|a, b| a.partial_cmp(b).unwrap());
/// assert_eq!(floats, [1.0, 2.0, 3.0, 4.0, 5.0]);
/// ```
///
/// When applicable, unstable sorting is preferred because it is generally faster than stable
/// sorting and it doesn't allocate auxiliary memory.
/// See [`sort_unstable_by`](slice::sort_unstable_by).
///
/// # Current implementation
///
/// The current algorithm is an adaptive, iterative merge sort inspired by
/// [timsort](https://en.wikipedia.org/wiki/Timsort).
/// It is designed to be very fast in cases where the slice is nearly sorted, or consists of
/// two or more sorted sequences concatenated one after another.
///
/// Also, it allocates temporary storage half the size of `self`, but for short slices a
/// non-allocating insertion sort is used instead.
///
/// # Examples
///
/// ```
/// let mut v = [5, 4, 1, 3, 2];
/// v.sort_by(|a, b| a.cmp(b));
/// assert!(v == [1, 2, 3, 4, 5]);
///
/// // reverse sorting
/// v.sort_by(|a, b| b.cmp(a));
/// assert!(v == [5, 4, 3, 2, 1]);
/// ```
#[cfg(not(no_global_oom_handling))]
#[rustc_allow_incoherent_impl]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn sort_by<F>(&mut self, mut compare: F)
where
F: FnMut(&T, &T) -> Ordering,
{
stable_sort(self, |a, b| compare(a, b) == Less);
}
/// Sorts the slice with a key extraction function.
///
/// This sort is stable (i.e., does not reorder equal elements) and *O*(*m* \* *n* \* log(*n*))
/// worst-case, where the key function is *O*(*m*).
///
/// For expensive key functions (e.g. functions that are not simple property accesses or
/// basic operations), [`sort_by_cached_key`](slice::sort_by_cached_key) is likely to be
/// significantly faster, as it does not recompute element keys.
///
/// When applicable, unstable sorting is preferred because it is generally faster than stable
/// sorting and it doesn't allocate auxiliary memory.
/// See [`sort_unstable_by_key`](slice::sort_unstable_by_key).
///
/// # Current implementation
///
/// The current algorithm is an adaptive, iterative merge sort inspired by
/// [timsort](https://en.wikipedia.org/wiki/Timsort).
/// It is designed to be very fast in cases where the slice is nearly sorted, or consists of
/// two or more sorted sequences concatenated one after another.
///
/// Also, it allocates temporary storage half the size of `self`, but for short slices a
/// non-allocating insertion sort is used instead.
///
/// # Examples
///
/// ```
/// let mut v = [-5i32, 4, 1, -3, 2];
///
/// v.sort_by_key(|k| k.abs());
/// assert!(v == [1, 2, -3, 4, -5]);
/// ```
#[cfg(not(no_global_oom_handling))]
#[rustc_allow_incoherent_impl]
#[stable(feature = "slice_sort_by_key", since = "1.7.0")]
#[inline]
pub fn sort_by_key<K, F>(&mut self, mut f: F)
where
F: FnMut(&T) -> K,
K: Ord,
{
stable_sort(self, |a, b| f(a).lt(&f(b)));
}
/// Sorts the slice with a key extraction function.
///
/// During sorting, the key function is called at most once per element, by using
/// temporary storage to remember the results of key evaluation.
/// The order of calls to the key function is unspecified and may change in future versions
/// of the standard library.
///
/// This sort is stable (i.e., does not reorder equal elements) and *O*(*m* \* *n* + *n* \* log(*n*))
/// worst-case, where the key function is *O*(*m*).
///
/// For simple key functions (e.g., functions that are property accesses or
/// basic operations), [`sort_by_key`](slice::sort_by_key) is likely to be
/// faster.
///
/// # Current implementation
///
/// The current algorithm is based on [pattern-defeating quicksort][pdqsort] by Orson Peters,
/// which combines the fast average case of randomized quicksort with the fast worst case of
/// heapsort, while achieving linear time on slices with certain patterns. It uses some
/// randomization to avoid degenerate cases, but with a fixed seed to always provide
/// deterministic behavior.
///
/// In the worst case, the algorithm allocates temporary storage in a `Vec<(K, usize)>` the
/// length of the slice.
///
/// # Examples
///
/// ```
/// let mut v = [-5i32, 4, 32, -3, 2];
///
/// v.sort_by_cached_key(|k| k.to_string());
/// assert!(v == [-3, -5, 2, 32, 4]);
/// ```
///
/// [pdqsort]: https://github.com/orlp/pdqsort
#[cfg(not(no_global_oom_handling))]
#[rustc_allow_incoherent_impl]
#[stable(feature = "slice_sort_by_cached_key", since = "1.34.0")]
#[inline]
pub fn sort_by_cached_key<K, F>(&mut self, f: F)
where
F: FnMut(&T) -> K,
K: Ord,
{
// Helper macro for indexing our vector by the smallest possible type, to reduce allocation.
macro_rules! sort_by_key {
($t:ty, $slice:ident, $f:ident) => {{
let mut indices: Vec<_> =
$slice.iter().map($f).enumerate().map(|(i, k)| (k, i as $t)).collect();
// The elements of `indices` are unique, as they are indexed, so any sort will be
// stable with respect to the original slice. We use `sort_unstable` here because
// it requires less memory allocation.
indices.sort_unstable();
for i in 0..$slice.len() {
let mut index = indices[i].1;
while (index as usize) < i {
index = indices[index as usize].1;
}
indices[i].1 = index;
$slice.swap(i, index as usize);
}
}};
}
let sz_u8 = mem::size_of::<(K, u8)>();
let sz_u16 = mem::size_of::<(K, u16)>();
let sz_u32 = mem::size_of::<(K, u32)>();
let sz_usize = mem::size_of::<(K, usize)>();
let len = self.len();
if len < 2 {
return;
}
if sz_u8 < sz_u16 && len <= (u8::MAX as usize) {
return sort_by_key!(u8, self, f);
}
if sz_u16 < sz_u32 && len <= (u16::MAX as usize) {
return sort_by_key!(u16, self, f);
}
if sz_u32 < sz_usize && len <= (u32::MAX as usize) {
return sort_by_key!(u32, self, f);
}
sort_by_key!(usize, self, f)
}
/// Copies `self` into a new `Vec`.
///
/// # Examples
///
/// ```
/// let s = [10, 40, 30];
/// let x = s.to_vec();
/// // Here, `s` and `x` can be modified independently.
/// ```
#[cfg(not(no_global_oom_handling))]
#[rustc_allow_incoherent_impl]
#[rustc_conversion_suggestion]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn to_vec(&self) -> Vec<T>
where
T: Clone,
{
self.to_vec_in(Global)
}
/// Copies `self` into a new `Vec` with an allocator.
///
/// # Examples
///
/// ```
/// #![feature(allocator_api)]
///
/// use std::alloc::System;
///
/// let s = [10, 40, 30];
/// let x = s.to_vec_in(System);
/// // Here, `s` and `x` can be modified independently.
/// ```
#[cfg(not(no_global_oom_handling))]
#[rustc_allow_incoherent_impl]
#[inline]
#[unstable(feature = "allocator_api", issue = "32838")]
pub fn to_vec_in<A: Allocator>(&self, alloc: A) -> Vec<T, A>
where
T: Clone,
{
// N.B., see the `hack` module in this file for more details.
hack::to_vec(self, alloc)
}
/// Converts `self` into a vector without clones or allocation.
///
/// The resulting vector can be converted back into a box via
/// `Vec<T>`'s `into_boxed_slice` method.
///
/// # Examples
///
/// ```
/// let s: Box<[i32]> = Box::new([10, 40, 30]);
/// let x = s.into_vec();
/// // `s` cannot be used anymore because it has been converted into `x`.
///
/// assert_eq!(x, vec![10, 40, 30]);
/// ```
#[rustc_allow_incoherent_impl]
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn into_vec<A: Allocator>(self: Box<Self, A>) -> Vec<T, A> {
// N.B., see the `hack` module in this file for more details.
hack::into_vec(self)
}
/// Creates a vector by copying a slice `n` times.
///
/// # Panics
///
/// This function will panic if the capacity would overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// assert_eq!([1, 2].repeat(3), vec![1, 2, 1, 2, 1, 2]);
/// ```
///
/// A panic upon overflow:
///
/// ```should_panic
/// // this will panic at runtime
/// b"0123456789abcdef".repeat(usize::MAX);
/// ```
#[rustc_allow_incoherent_impl]
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "repeat_generic_slice", since = "1.40.0")]
pub fn repeat(&self, n: usize) -> Vec<T>
where
T: Copy,
{
if n == 0 {
return Vec::new();
}
// If `n` is larger than zero, it can be split as
// `n = 2^expn + rem (2^expn > rem, expn >= 0, rem >= 0)`.
// `2^expn` is the number represented by the leftmost '1' bit of `n`,
// and `rem` is the remaining part of `n`.
// Using `Vec` to access `set_len()`.
let capacity = self.len().checked_mul(n).expect("capacity overflow");
let mut buf = Vec::with_capacity(capacity);
// `2^expn` repetition is done by doubling `buf` `expn`-times.
buf.extend(self);
{
let mut m = n >> 1;
// If `m > 0`, there are remaining bits up to the leftmost '1'.
while m > 0 {
// `buf.extend(buf)`:
unsafe {
ptr::copy_nonoverlapping(
buf.as_ptr(),
(buf.as_mut_ptr() as *mut T).add(buf.len()),
buf.len(),
);
// `buf` has capacity of `self.len() * n`.
let buf_len = buf.len();
buf.set_len(buf_len * 2);
}
m >>= 1;
}
}
// `rem` (`= n - 2^expn`) repetition is done by copying
// first `rem` repetitions from `buf` itself.
let rem_len = capacity - buf.len(); // `self.len() * rem`
if rem_len > 0 {
// `buf.extend(buf[0 .. rem_len])`:
unsafe {
// This is non-overlapping since `2^expn > rem`.
ptr::copy_nonoverlapping(
buf.as_ptr(),
(buf.as_mut_ptr() as *mut T).add(buf.len()),
rem_len,
);
// `buf.len() + rem_len` equals to `buf.capacity()` (`= self.len() * n`).
buf.set_len(capacity);
}
}
buf
}
/// Flattens a slice of `T` into a single value `Self::Output`.
///
/// # Examples
///
/// ```
/// assert_eq!(["hello", "world"].concat(), "helloworld");
/// assert_eq!([[1, 2], [3, 4]].concat(), [1, 2, 3, 4]);
/// ```
#[rustc_allow_incoherent_impl]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn concat<Item: ?Sized>(&self) -> <Self as Concat<Item>>::Output
where
Self: Concat<Item>,
{
Concat::concat(self)
}
/// Flattens a slice of `T` into a single value `Self::Output`, placing a
/// given separator between each.
///
/// # Examples
///
/// ```
/// assert_eq!(["hello", "world"].join(" "), "hello world");
/// assert_eq!([[1, 2], [3, 4]].join(&0), [1, 2, 0, 3, 4]);
/// assert_eq!([[1, 2], [3, 4]].join(&[0, 0][..]), [1, 2, 0, 0, 3, 4]);
/// ```
#[rustc_allow_incoherent_impl]
#[stable(feature = "rename_connect_to_join", since = "1.3.0")]
pub fn join<Separator>(&self, sep: Separator) -> <Self as Join<Separator>>::Output
where
Self: Join<Separator>,
{
Join::join(self, sep)
}
/// Flattens a slice of `T` into a single value `Self::Output`, placing a
/// given separator between each.
///
/// # Examples
///
/// ```
/// # #![allow(deprecated)]
/// assert_eq!(["hello", "world"].connect(" "), "hello world");
/// assert_eq!([[1, 2], [3, 4]].connect(&0), [1, 2, 0, 3, 4]);
/// ```
#[rustc_allow_incoherent_impl]
#[stable(feature = "rust1", since = "1.0.0")]
#[deprecated(since = "1.3.0", note = "renamed to join", suggestion = "join")]
pub fn connect<Separator>(&self, sep: Separator) -> <Self as Join<Separator>>::Output
where
Self: Join<Separator>,
{
Join::join(self, sep)
}
}
#[cfg(not(test))]
impl [u8] {
/// Returns a vector containing a copy of this slice where each byte
/// is mapped to its ASCII upper case equivalent.
///
/// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
/// but non-ASCII letters are unchanged.
///
/// To uppercase the value in-place, use [`make_ascii_uppercase`].
///
/// [`make_ascii_uppercase`]: slice::make_ascii_uppercase
#[cfg(not(no_global_oom_handling))]
#[rustc_allow_incoherent_impl]
#[must_use = "this returns the uppercase bytes as a new Vec, \
without modifying the original"]
#[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
#[inline]
pub fn to_ascii_uppercase(&self) -> Vec<u8> {
let mut me = self.to_vec();
me.make_ascii_uppercase();
me
}
/// Returns a vector containing a copy of this slice where each byte
/// is mapped to its ASCII lower case equivalent.
///
/// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z',
/// but non-ASCII letters are unchanged.
///
/// To lowercase the value in-place, use [`make_ascii_lowercase`].
///
/// [`make_ascii_lowercase`]: slice::make_ascii_lowercase
#[cfg(not(no_global_oom_handling))]
#[rustc_allow_incoherent_impl]
#[must_use = "this returns the lowercase bytes as a new Vec, \
without modifying the original"]
#[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
#[inline]
pub fn to_ascii_lowercase(&self) -> Vec<u8> {
let mut me = self.to_vec();
me.make_ascii_lowercase();
me
}
}
////////////////////////////////////////////////////////////////////////////////
// Extension traits for slices over specific kinds of data
////////////////////////////////////////////////////////////////////////////////
/// Helper trait for [`[T]::concat`](slice::concat).
///
/// Note: the `Item` type parameter is not used in this trait,
/// but it allows impls to be more generic.
/// Without it, we get this error:
///
/// ```error
/// error[E0207]: the type parameter `T` is not constrained by the impl trait, self type, or predica
/// --> library/alloc/src/slice.rs:608:6
/// |
/// 608 | impl<T: Clone, V: Borrow<[T]>> Concat for [V] {
/// | ^ unconstrained type parameter
/// ```
///
/// This is because there could exist `V` types with multiple `Borrow<[_]>` impls,
/// such that multiple `T` types would apply:
///
/// ```
/// # #[allow(dead_code)]
/// pub struct Foo(Vec<u32>, Vec<String>);
///
/// impl std::borrow::Borrow<[u32]> for Foo {
/// fn borrow(&self) -> &[u32] { &self.0 }
/// }
///
/// impl std::borrow::Borrow<[String]> for Foo {
/// fn borrow(&self) -> &[String] { &self.1 }
/// }
/// ```
#[unstable(feature = "slice_concat_trait", issue = "27747")]
pub trait Concat<Item: ?Sized> {
#[unstable(feature = "slice_concat_trait", issue = "27747")]
/// The resulting type after concatenation
type Output;
/// Implementation of [`[T]::concat`](slice::concat)
#[unstable(feature = "slice_concat_trait", issue = "27747")]
fn concat(slice: &Self) -> Self::Output;
}
/// Helper trait for [`[T]::join`](slice::join)
#[unstable(feature = "slice_concat_trait", issue = "27747")]
pub trait Join<Separator> {
#[unstable(feature = "slice_concat_trait", issue = "27747")]
/// The resulting type after concatenation
type Output;
/// Implementation of [`[T]::join`](slice::join)
#[unstable(feature = "slice_concat_trait", issue = "27747")]
fn join(slice: &Self, sep: Separator) -> Self::Output;
}
#[cfg(not(no_global_oom_handling))]
#[unstable(feature = "slice_concat_ext", issue = "27747")]
impl<T: Clone, V: Borrow<[T]>> Concat<T> for [V] {
type Output = Vec<T>;
fn concat(slice: &Self) -> Vec<T> {
let size = slice.iter().map(|slice| slice.borrow().len()).sum();
let mut result = Vec::with_capacity(size);
for v in slice {
result.extend_from_slice(v.borrow())
}
result
}
}
#[cfg(not(no_global_oom_handling))]
#[unstable(feature = "slice_concat_ext", issue = "27747")]
impl<T: Clone, V: Borrow<[T]>> Join<&T> for [V] {
type Output = Vec<T>;
fn join(slice: &Self, sep: &T) -> Vec<T> {
let mut iter = slice.iter();
let first = match iter.next() {
Some(first) => first,
None => return vec![],
};
let size = slice.iter().map(|v| v.borrow().len()).sum::<usize>() + slice.len() - 1;
let mut result = Vec::with_capacity(size);
result.extend_from_slice(first.borrow());
for v in iter {
result.push(sep.clone());
result.extend_from_slice(v.borrow())
}
result
}
}
#[cfg(not(no_global_oom_handling))]
#[unstable(feature = "slice_concat_ext", issue = "27747")]
impl<T: Clone, V: Borrow<[T]>> Join<&[T]> for [V] {
type Output = Vec<T>;
fn join(slice: &Self, sep: &[T]) -> Vec<T> {
let mut iter = slice.iter();
let first = match iter.next() {
Some(first) => first,
None => return vec![],
};
let size =
slice.iter().map(|v| v.borrow().len()).sum::<usize>() + sep.len() * (slice.len() - 1);
let mut result = Vec::with_capacity(size);
result.extend_from_slice(first.borrow());
for v in iter {
result.extend_from_slice(sep);
result.extend_from_slice(v.borrow())
}
result
}
}
////////////////////////////////////////////////////////////////////////////////
// Standard trait implementations for slices
////////////////////////////////////////////////////////////////////////////////
#[stable(feature = "rust1", since = "1.0.0")]
impl<T, A: Allocator> Borrow<[T]> for Vec<T, A> {
fn borrow(&self) -> &[T] {
&self[..]
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T, A: Allocator> BorrowMut<[T]> for Vec<T, A> {
fn borrow_mut(&mut self) -> &mut [T] {
&mut self[..]
}
}
// Specializable trait for implementing ToOwned::clone_into. This is
// public in the crate and has the Allocator parameter so that
// vec::clone_from use it too.
#[cfg(not(no_global_oom_handling))]
pub(crate) trait SpecCloneIntoVec<T, A: Allocator> {
fn clone_into(&self, target: &mut Vec<T, A>);
}
#[cfg(not(no_global_oom_handling))]
impl<T: Clone, A: Allocator> SpecCloneIntoVec<T, A> for [T] {
default fn clone_into(&self, target: &mut Vec<T, A>) {
// drop anything in target that will not be overwritten
target.truncate(self.len());
// target.len <= self.len due to the truncate above, so the
// slices here are always in-bounds.
let (init, tail) = self.split_at(target.len());
// reuse the contained values' allocations/resources.
target.clone_from_slice(init);
target.extend_from_slice(tail);
}
}
#[cfg(not(no_global_oom_handling))]
impl<T: Copy, A: Allocator> SpecCloneIntoVec<T, A> for [T] {
fn clone_into(&self, target: &mut Vec<T, A>) {
target.clear();
target.extend_from_slice(self);
}
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: Clone> ToOwned for [T] {
type Owned = Vec<T>;
#[cfg(not(test))]
fn to_owned(&self) -> Vec<T> {
self.to_vec()
}
#[cfg(test)]
fn to_owned(&self) -> Vec<T> {
hack::to_vec(self, Global)
}
fn clone_into(&self, target: &mut Vec<T>) {
SpecCloneIntoVec::clone_into(self, target);
}
}
////////////////////////////////////////////////////////////////////////////////
// Sorting
////////////////////////////////////////////////////////////////////////////////
#[inline]
#[cfg(not(no_global_oom_handling))]
fn stable_sort<T, F>(v: &mut [T], mut is_less: F)
where
F: FnMut(&T, &T) -> bool,
{
if T::IS_ZST {
// Sorting has no meaningful behavior on zero-sized types. Do nothing.
return;
}
let elem_alloc_fn = |len: usize| -> *mut T {
// SAFETY: Creating the layout is safe as long as merge_sort never calls this with len >
// v.len(). Alloc in general will only be used as 'shadow-region' to store temporary swap
// elements.
unsafe { alloc::alloc(alloc::Layout::array::<T>(len).unwrap_unchecked()) as *mut T }
};
let elem_dealloc_fn = |buf_ptr: *mut T, len: usize| {
// SAFETY: Creating the layout is safe as long as merge_sort never calls this with len >
// v.len(). The caller must ensure that buf_ptr was created by elem_alloc_fn with the same
// len.
unsafe {
alloc::dealloc(buf_ptr as *mut u8, alloc::Layout::array::<T>(len).unwrap_unchecked());
}
};
let run_alloc_fn = |len: usize| -> *mut sort::TimSortRun {
// SAFETY: Creating the layout is safe as long as merge_sort never calls this with an
// obscene length or 0.
unsafe {
alloc::alloc(alloc::Layout::array::<sort::TimSortRun>(len).unwrap_unchecked())
as *mut sort::TimSortRun
}
};
let run_dealloc_fn = |buf_ptr: *mut sort::TimSortRun, len: usize| {
// SAFETY: The caller must ensure that buf_ptr was created by elem_alloc_fn with the same
// len.
unsafe {
alloc::dealloc(
buf_ptr as *mut u8,
alloc::Layout::array::<sort::TimSortRun>(len).unwrap_unchecked(),
);
}
};
sort::merge_sort(v, &mut is_less, elem_alloc_fn, elem_dealloc_fn, run_alloc_fn, run_dealloc_fn);
}
rust/alloc/vec/drain.rs deleted 100644 → 0
View file @ 84c7d76b
// SPDX-License-Identifier: Apache-2.0 OR MIT
use crate::alloc::{Allocator, Global};
use core::fmt;
use core::iter::{FusedIterator, TrustedLen};
use core::mem::{self, ManuallyDrop, SizedTypeProperties};
use core::ptr::{self, NonNull};
use core::slice::{self};
use super::Vec;
/// A draining iterator for `Vec<T>`.
///
/// This `struct` is created by [`Vec::drain`].
/// See its documentation for more.
///
/// # Example
///
/// ```
/// let mut v = vec![0, 1, 2];
/// let iter: std::vec::Drain<'_, _> = v.drain(..);
/// ```
#[stable(feature = "drain", since = "1.6.0")]
pub struct Drain<
'a,
T: 'a,
#[unstable(feature = "allocator_api", issue = "32838")] A: Allocator + 'a = Global,
> {
/// Index of tail to preserve
pub(super) tail_start: usize,
/// Length of tail
pub(super) tail_len: usize,
/// Current remaining range to remove
pub(super) iter: slice::Iter<'a, T>,
pub(super) vec: NonNull<Vec<T, A>>,
}
#[stable(feature = "collection_debug", since = "1.17.0")]
impl<T: fmt::Debug, A: Allocator> fmt::Debug for Drain<'_, T, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_tuple("Drain").field(&self.iter.as_slice()).finish()
}
}
impl<'a, T, A: Allocator> Drain<'a, T, A> {
/// Returns the remaining items of this iterator as a slice.
///
/// # Examples
///
/// ```
/// let mut vec = vec!['a', 'b', 'c'];
/// let mut drain = vec.drain(..);
/// assert_eq!(drain.as_slice(), &['a', 'b', 'c']);
/// let _ = drain.next().unwrap();
/// assert_eq!(drain.as_slice(), &['b', 'c']);
/// ```
#[must_use]
#[stable(feature = "vec_drain_as_slice", since = "1.46.0")]
pub fn as_slice(&self) -> &[T] {
self.iter.as_slice()
}
/// Returns a reference to the underlying allocator.
#[unstable(feature = "allocator_api", issue = "32838")]
#[must_use]
#[inline]
pub fn allocator(&self) -> &A {
unsafe { self.vec.as_ref().allocator() }
}
/// Keep unyielded elements in the source `Vec`.
///
/// # Examples
///
/// ```
/// #![feature(drain_keep_rest)]
///
/// let mut vec = vec!['a', 'b', 'c'];
/// let mut drain = vec.drain(..);
///
/// assert_eq!(drain.next().unwrap(), 'a');
///
/// // This call keeps 'b' and 'c' in the vec.
/// drain.keep_rest();
///
/// // If we wouldn't call `keep_rest()`,
/// // `vec` would be empty.
/// assert_eq!(vec, ['b', 'c']);
/// ```
#[unstable(feature = "drain_keep_rest", issue = "101122")]
pub fn keep_rest(self) {
// At this moment layout looks like this:
//
// [head] [yielded by next] [unyielded] [yielded by next_back] [tail]
// ^-- start \_________/-- unyielded_len \____/-- self.tail_len
// ^-- unyielded_ptr ^-- tail
//
// Normally `Drop` impl would drop [unyielded] and then move [tail] to the `start`.
// Here we want to
// 1. Move [unyielded] to `start`
// 2. Move [tail] to a new start at `start + len(unyielded)`
// 3. Update length of the original vec to `len(head) + len(unyielded) + len(tail)`
// a. In case of ZST, this is the only thing we want to do
// 4. Do *not* drop self, as everything is put in a consistent state already, there is nothing to do
let mut this = ManuallyDrop::new(self);
unsafe {
let source_vec = this.vec.as_mut();
let start = source_vec.len();
let tail = this.tail_start;
let unyielded_len = this.iter.len();
let unyielded_ptr = this.iter.as_slice().as_ptr();
// ZSTs have no identity, so we don't need to move them around.
if !T::IS_ZST {
let start_ptr = source_vec.as_mut_ptr().add(start);
// memmove back unyielded elements
if unyielded_ptr != start_ptr {
let src = unyielded_ptr;
let dst = start_ptr;
ptr::copy(src, dst, unyielded_len);
}
// memmove back untouched tail
if tail != (start + unyielded_len) {
let src = source_vec.as_ptr().add(tail);
let dst = start_ptr.add(unyielded_len);
ptr::copy(src, dst, this.tail_len);
}
}
source_vec.set_len(start + unyielded_len + this.tail_len);
}
}
}
#[stable(feature = "vec_drain_as_slice", since = "1.46.0")]
impl<'a, T, A: Allocator> AsRef<[T]> for Drain<'a, T, A> {
fn as_ref(&self) -> &[T] {
self.as_slice()
}
}
#[stable(feature = "drain", since = "1.6.0")]
unsafe impl<T: Sync, A: Sync + Allocator> Sync for Drain<'_, T, A> {}
#[stable(feature = "drain", since = "1.6.0")]
unsafe impl<T: Send, A: Send + Allocator> Send for Drain<'_, T, A> {}
#[stable(feature = "drain", since = "1.6.0")]
impl<T, A: Allocator> Iterator for Drain<'_, T, A> {
type Item = T;
#[inline]
fn next(&mut self) -> Option<T> {
self.iter.next().map(|elt| unsafe { ptr::read(elt as *const _) })
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
#[stable(feature = "drain", since = "1.6.0")]
impl<T, A: Allocator> DoubleEndedIterator for Drain<'_, T, A> {
#[inline]
fn next_back(&mut self) -> Option<T> {
self.iter.next_back().map(|elt| unsafe { ptr::read(elt as *const _) })
}
}
#[stable(feature = "drain", since = "1.6.0")]
impl<T, A: Allocator> Drop for Drain<'_, T, A> {
fn drop(&mut self) {
/// Moves back the un-`Drain`ed elements to restore the original `Vec`.
struct DropGuard<'r, 'a, T, A: Allocator>(&'r mut Drain<'a, T, A>);
impl<'r, 'a, T, A: Allocator> Drop for DropGuard<'r, 'a, T, A> {
fn drop(&mut self) {
if self.0.tail_len > 0 {
unsafe {
let source_vec = self.0.vec.as_mut();
// memmove back untouched tail, update to new length
let start = source_vec.len();
let tail = self.0.tail_start;
if tail != start {
let src = source_vec.as_ptr().add(tail);
let dst = source_vec.as_mut_ptr().add(start);
ptr::copy(src, dst, self.0.tail_len);
}
source_vec.set_len(start + self.0.tail_len);
}
}
}
}
let iter = mem::take(&mut self.iter);
let drop_len = iter.len();
let mut vec = self.vec;
if T::IS_ZST {
// ZSTs have no identity, so we don't need to move them around, we only need to drop the correct amount.
// this can be achieved by manipulating the Vec length instead of moving values out from `iter`.
unsafe {
let vec = vec.as_mut();
let old_len = vec.len();
vec.set_len(old_len + drop_len + self.tail_len);
vec.truncate(old_len + self.tail_len);
}
return;
}
// ensure elements are moved back into their appropriate places, even when drop_in_place panics
let _guard = DropGuard(self);
if drop_len == 0 {
return;
}
// as_slice() must only be called when iter.len() is > 0 because
// it also gets touched by vec::Splice which may turn it into a dangling pointer
// which would make it and the vec pointer point to different allocations which would
// lead to invalid pointer arithmetic below.
let drop_ptr = iter.as_slice().as_ptr();
unsafe {
// drop_ptr comes from a slice::Iter which only gives us a &[T] but for drop_in_place
// a pointer with mutable provenance is necessary. Therefore we must reconstruct
// it from the original vec but also avoid creating a &mut to the front since that could
// invalidate raw pointers to it which some unsafe code might rely on.
let vec_ptr = vec.as_mut().as_mut_ptr();
let drop_offset = drop_ptr.sub_ptr(vec_ptr);
let to_drop = ptr::slice_from_raw_parts_mut(vec_ptr.add(drop_offset), drop_len);
ptr::drop_in_place(to_drop);
}
}
}
#[stable(feature = "drain", since = "1.6.0")]
impl<T, A: Allocator> ExactSizeIterator for Drain<'_, T, A> {
fn is_empty(&self) -> bool {
self.iter.is_empty()
}
}
#[unstable(feature = "trusted_len", issue = "37572")]
unsafe impl<T, A: Allocator> TrustedLen for Drain<'_, T, A> {}
#[stable(feature = "fused", since = "1.26.0")]
impl<T, A: Allocator> FusedIterator for Drain<'_, T, A> {}
rust/alloc/vec/extract_if.rs deleted 100644 → 0
View file @ 84c7d76b
// SPDX-License-Identifier: Apache-2.0 OR MIT
use crate::alloc::{Allocator, Global};
use core::ptr;
use core::slice;
use super::Vec;
/// An iterator which uses a closure to determine if an element should be removed.
///
/// This struct is created by [`Vec::extract_if`].
/// See its documentation for more.
///
/// # Example
///
/// ```
/// #![feature(extract_if)]
///
/// let mut v = vec![0, 1, 2];
/// let iter: std::vec::ExtractIf<'_, _, _> = v.extract_if(|x| *x % 2 == 0);
/// ```
#[unstable(feature = "extract_if", reason = "recently added", issue = "43244")]
#[derive(Debug)]
#[must_use = "iterators are lazy and do nothing unless consumed"]
pub struct ExtractIf<
'a,
T,
F,
#[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global,
> where
F: FnMut(&mut T) -> bool,
{
pub(super) vec: &'a mut Vec<T, A>,
/// The index of the item that will be inspected by the next call to `next`.
pub(super) idx: usize,
/// The number of items that have been drained (removed) thus far.
pub(super) del: usize,
/// The original length of `vec` prior to draining.
pub(super) old_len: usize,
/// The filter test predicate.
pub(super) pred: F,
}
impl<T, F, A: Allocator> ExtractIf<'_, T, F, A>
where
F: FnMut(&mut T) -> bool,
{
/// Returns a reference to the underlying allocator.
#[unstable(feature = "allocator_api", issue = "32838")]
#[inline]
pub fn allocator(&self) -> &A {
self.vec.allocator()
}
}
#[unstable(feature = "extract_if", reason = "recently added", issue = "43244")]
impl<T, F, A: Allocator> Iterator for ExtractIf<'_, T, F, A>
where
F: FnMut(&mut T) -> bool,
{
type Item = T;
fn next(&mut self) -> Option<T> {
unsafe {
while self.idx < self.old_len {
let i = self.idx;
let v = slice::from_raw_parts_mut(self.vec.as_mut_ptr(), self.old_len);
let drained = (self.pred)(&mut v[i]);
// Update the index *after* the predicate is called. If the index
// is updated prior and the predicate panics, the element at this
// index would be leaked.
self.idx += 1;
if drained {
self.del += 1;
return Some(ptr::read(&v[i]));
} else if self.del > 0 {
let del = self.del;
let src: *const T = &v[i];
let dst: *mut T = &mut v[i - del];
ptr::copy_nonoverlapping(src, dst, 1);
}
}
None
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
(0, Some(self.old_len - self.idx))
}
}
#[unstable(feature = "extract_if", reason = "recently added", issue = "43244")]
impl<T, F, A: Allocator> Drop for ExtractIf<'_, T, F, A>
where
F: FnMut(&mut T) -> bool,
{
fn drop(&mut self) {
unsafe {
if self.idx < self.old_len && self.del > 0 {
// This is a pretty messed up state, and there isn't really an
// obviously right thing to do. We don't want to keep trying
// to execute `pred`, so we just backshift all the unprocessed
// elements and tell the vec that they still exist. The backshift
// is required to prevent a double-drop of the last successfully
// drained item prior to a panic in the predicate.
let ptr = self.vec.as_mut_ptr();
let src = ptr.add(self.idx);
let dst = src.sub(self.del);
let tail_len = self.old_len - self.idx;
src.copy_to(dst, tail_len);
}
self.vec.set_len(self.old_len - self.del);
}
}
}
rust/alloc/vec/into_iter.rs deleted 100644 → 0
View file @ 84c7d76b
// SPDX-License-Identifier: Apache-2.0 OR MIT
#[cfg(not(no_global_oom_handling))]
use super::AsVecIntoIter;
use crate::alloc::{Allocator, Global};
#[cfg(not(no_global_oom_handling))]
use crate::collections::VecDeque;
use crate::raw_vec::RawVec;
use core::array;
use core::fmt;
use core::iter::{
FusedIterator, InPlaceIterable, SourceIter, TrustedFused, TrustedLen,
TrustedRandomAccessNoCoerce,
};
use core::marker::PhantomData;
use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties};
use core::num::NonZeroUsize;
#[cfg(not(no_global_oom_handling))]
use core::ops::Deref;
use core::ptr::{self, NonNull};
use core::slice::{self};
/// An iterator that moves out of a vector.
///
/// This `struct` is created by the `into_iter` method on [`Vec`](super::Vec)
/// (provided by the [`IntoIterator`] trait).
///
/// # Example
///
/// ```
/// let v = vec![0, 1, 2];
/// let iter: std::vec::IntoIter<_> = v.into_iter();
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_insignificant_dtor]
pub struct IntoIter<
T,
#[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global,
> {
pub(super) buf: NonNull<T>,
pub(super) phantom: PhantomData<T>,
pub(super) cap: usize,
// the drop impl reconstructs a RawVec from buf, cap and alloc
// to avoid dropping the allocator twice we need to wrap it into ManuallyDrop
pub(super) alloc: ManuallyDrop<A>,
pub(super) ptr: *const T,
pub(super) end: *const T, // If T is a ZST, this is actually ptr+len. This encoding is picked so that
// ptr == end is a quick test for the Iterator being empty, that works
// for both ZST and non-ZST.
}
#[stable(feature = "vec_intoiter_debug", since = "1.13.0")]
impl<T: fmt::Debug, A: Allocator> fmt::Debug for IntoIter<T, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_tuple("IntoIter").field(&self.as_slice()).finish()
}
}
impl<T, A: Allocator> IntoIter<T, A> {
/// Returns the remaining items of this iterator as a slice.
///
/// # Examples
///
/// ```
/// let vec = vec!['a', 'b', 'c'];
/// let mut into_iter = vec.into_iter();
/// assert_eq!(into_iter.as_slice(), &['a', 'b', 'c']);
/// let _ = into_iter.next().unwrap();
/// assert_eq!(into_iter.as_slice(), &['b', 'c']);
/// ```
#[stable(feature = "vec_into_iter_as_slice", since = "1.15.0")]
pub fn as_slice(&self) -> &[T] {
unsafe { slice::from_raw_parts(self.ptr, self.len()) }
}
/// Returns the remaining items of this iterator as a mutable slice.
///
/// # Examples
///
/// ```
/// let vec = vec!['a', 'b', 'c'];
/// let mut into_iter = vec.into_iter();
/// assert_eq!(into_iter.as_slice(), &['a', 'b', 'c']);
/// into_iter.as_mut_slice()[2] = 'z';
/// assert_eq!(into_iter.next().unwrap(), 'a');
/// assert_eq!(into_iter.next().unwrap(), 'b');
/// assert_eq!(into_iter.next().unwrap(), 'z');
/// ```
#[stable(feature = "vec_into_iter_as_slice", since = "1.15.0")]
pub fn as_mut_slice(&mut self) -> &mut [T] {
unsafe { &mut *self.as_raw_mut_slice() }
}
/// Returns a reference to the underlying allocator.
#[unstable(feature = "allocator_api", issue = "32838")]
#[inline]
pub fn allocator(&self) -> &A {
&self.alloc
}
fn as_raw_mut_slice(&mut self) -> *mut [T] {
ptr::slice_from_raw_parts_mut(self.ptr as *mut T, self.len())
}
/// Drops remaining elements and relinquishes the backing allocation.
/// This method guarantees it won't panic before relinquishing
/// the backing allocation.
///
/// This is roughly equivalent to the following, but more efficient
///
/// ```
/// # let mut into_iter = Vec::<u8>::with_capacity(10).into_iter();
/// let mut into_iter = std::mem::replace(&mut into_iter, Vec::new().into_iter());
/// (&mut into_iter).for_each(drop);
/// std::mem::forget(into_iter);
/// ```
///
/// This method is used by in-place iteration, refer to the vec::in_place_collect
/// documentation for an overview.
#[cfg(not(no_global_oom_handling))]
pub(super) fn forget_allocation_drop_remaining(&mut self) {
let remaining = self.as_raw_mut_slice();
// overwrite the individual fields instead of creating a new
// struct and then overwriting &mut self.
// this creates less assembly
self.cap = 0;
self.buf = unsafe { NonNull::new_unchecked(RawVec::NEW.ptr()) };
self.ptr = self.buf.as_ptr();
self.end = self.buf.as_ptr();
// Dropping the remaining elements can panic, so this needs to be
// done only after updating the other fields.
unsafe {
ptr::drop_in_place(remaining);
}
}
/// Forgets to Drop the remaining elements while still allowing the backing allocation to be freed.
pub(crate) fn forget_remaining_elements(&mut self) {
// For th ZST case, it is crucial that we mutate `end` here, not `ptr`.
// `ptr` must stay aligned, while `end` may be unaligned.
self.end = self.ptr;
}
#[cfg(not(no_global_oom_handling))]
#[inline]
pub(crate) fn into_vecdeque(self) -> VecDeque<T, A> {
// Keep our `Drop` impl from dropping the elements and the allocator
let mut this = ManuallyDrop::new(self);
// SAFETY: This allocation originally came from a `Vec`, so it passes
// all those checks. We have `this.buf` ≤ `this.ptr` ≤ `this.end`,
// so the `sub_ptr`s below cannot wrap, and will produce a well-formed
// range. `end` ≤ `buf + cap`, so the range will be in-bounds.
// Taking `alloc` is ok because nothing else is going to look at it,
// since our `Drop` impl isn't going to run so there's no more code.
unsafe {
let buf = this.buf.as_ptr();
let initialized = if T::IS_ZST {
// All the pointers are the same for ZSTs, so it's fine to
// say that they're all at the beginning of the "allocation".
0..this.len()
} else {
this.ptr.sub_ptr(buf)..this.end.sub_ptr(buf)
};
let cap = this.cap;
let alloc = ManuallyDrop::take(&mut this.alloc);
VecDeque::from_contiguous_raw_parts_in(buf, initialized, cap, alloc)
}
}
}
#[stable(feature = "vec_intoiter_as_ref", since = "1.46.0")]
impl<T, A: Allocator> AsRef<[T]> for IntoIter<T, A> {
fn as_ref(&self) -> &[T] {
self.as_slice()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
unsafe impl<T: Send, A: Allocator + Send> Send for IntoIter<T, A> {}
#[stable(feature = "rust1", since = "1.0.0")]
unsafe impl<T: Sync, A: Allocator + Sync> Sync for IntoIter<T, A> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T, A: Allocator> Iterator for IntoIter<T, A> {
type Item = T;
#[inline]
fn next(&mut self) -> Option<T> {
if self.ptr == self.end {
None
} else if T::IS_ZST {
// `ptr` has to stay where it is to remain aligned, so we reduce the length by 1 by
// reducing the `end`.
self.end = self.end.wrapping_byte_sub(1);
// Make up a value of this ZST.
Some(unsafe { mem::zeroed() })
} else {
let old = self.ptr;
self.ptr = unsafe { self.ptr.add(1) };
Some(unsafe { ptr::read(old) })
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let exact = if T::IS_ZST {
self.end.addr().wrapping_sub(self.ptr.addr())
} else {
unsafe { self.end.sub_ptr(self.ptr) }
};
(exact, Some(exact))
}
#[inline]
fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize> {
let step_size = self.len().min(n);
let to_drop = ptr::slice_from_raw_parts_mut(self.ptr as *mut T, step_size);
if T::IS_ZST {
// See `next` for why we sub `end` here.
self.end = self.end.wrapping_byte_sub(step_size);
} else {
// SAFETY: the min() above ensures that step_size is in bounds
self.ptr = unsafe { self.ptr.add(step_size) };
}
// SAFETY: the min() above ensures that step_size is in bounds
unsafe {
ptr::drop_in_place(to_drop);
}
NonZeroUsize::new(n - step_size).map_or(Ok(()), Err)
}
#[inline]
fn count(self) -> usize {
self.len()
}
#[inline]
fn next_chunk<const N: usize>(&mut self) -> Result<[T; N], core::array::IntoIter<T, N>> {
let mut raw_ary = MaybeUninit::uninit_array();
let len = self.len();
if T::IS_ZST {
if len < N {
self.forget_remaining_elements();
// Safety: ZSTs can be conjured ex nihilo, only the amount has to be correct
return Err(unsafe { array::IntoIter::new_unchecked(raw_ary, 0..len) });
}
self.end = self.end.wrapping_byte_sub(N);
// Safety: ditto
return Ok(unsafe { raw_ary.transpose().assume_init() });
}
if len < N {
// Safety: `len` indicates that this many elements are available and we just checked that
// it fits into the array.
unsafe {
ptr::copy_nonoverlapping(self.ptr, raw_ary.as_mut_ptr() as *mut T, len);
self.forget_remaining_elements();
return Err(array::IntoIter::new_unchecked(raw_ary, 0..len));
}
}
// Safety: `len` is larger than the array size. Copy a fixed amount here to fully initialize
// the array.
return unsafe {
ptr::copy_nonoverlapping(self.ptr, raw_ary.as_mut_ptr() as *mut T, N);
self.ptr = self.ptr.add(N);
Ok(raw_ary.transpose().assume_init())
};
}
unsafe fn __iterator_get_unchecked(&mut self, i: usize) -> Self::Item
where
Self: TrustedRandomAccessNoCoerce,
{
// SAFETY: the caller must guarantee that `i` is in bounds of the
// `Vec<T>`, so `i` cannot overflow an `isize`, and the `self.ptr.add(i)`
// is guaranteed to pointer to an element of the `Vec<T>` and
// thus guaranteed to be valid to dereference.
//
// Also note the implementation of `Self: TrustedRandomAccess` requires
// that `T: Copy` so reading elements from the buffer doesn't invalidate
// them for `Drop`.
unsafe { if T::IS_ZST { mem::zeroed() } else { ptr::read(self.ptr.add(i)) } }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T, A: Allocator> DoubleEndedIterator for IntoIter<T, A> {
#[inline]
fn next_back(&mut self) -> Option<T> {
if self.end == self.ptr {
None
} else if T::IS_ZST {
// See above for why 'ptr.offset' isn't used
self.end = self.end.wrapping_byte_sub(1);
// Make up a value of this ZST.
Some(unsafe { mem::zeroed() })
} else {
self.end = unsafe { self.end.sub(1) };
Some(unsafe { ptr::read(self.end) })
}
}
#[inline]
fn advance_back_by(&mut self, n: usize) -> Result<(), NonZeroUsize> {
let step_size = self.len().min(n);
if T::IS_ZST {
// SAFETY: same as for advance_by()
self.end = self.end.wrapping_byte_sub(step_size);
} else {
// SAFETY: same as for advance_by()
self.end = unsafe { self.end.sub(step_size) };
}
let to_drop = ptr::slice_from_raw_parts_mut(self.end as *mut T, step_size);
// SAFETY: same as for advance_by()
unsafe {
ptr::drop_in_place(to_drop);
}
NonZeroUsize::new(n - step_size).map_or(Ok(()), Err)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T, A: Allocator> ExactSizeIterator for IntoIter<T, A> {
fn is_empty(&self) -> bool {
self.ptr == self.end
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<T, A: Allocator> FusedIterator for IntoIter<T, A> {}
#[doc(hidden)]
#[unstable(issue = "none", feature = "trusted_fused")]
unsafe impl<T, A: Allocator> TrustedFused for IntoIter<T, A> {}
#[unstable(feature = "trusted_len", issue = "37572")]
unsafe impl<T, A: Allocator> TrustedLen for IntoIter<T, A> {}
#[stable(feature = "default_iters", since = "1.70.0")]
impl<T, A> Default for IntoIter<T, A>
where
A: Allocator + Default,
{
/// Creates an empty `vec::IntoIter`.
///
/// ```
/// # use std::vec;
/// let iter: vec::IntoIter<u8> = Default::default();
/// assert_eq!(iter.len(), 0);
/// assert_eq!(iter.as_slice(), &[]);
/// ```
fn default() -> Self {
super::Vec::new_in(Default::default()).into_iter()
}
}
#[doc(hidden)]
#[unstable(issue = "none", feature = "std_internals")]
#[rustc_unsafe_specialization_marker]
pub trait NonDrop {}
// T: Copy as approximation for !Drop since get_unchecked does not advance self.ptr
// and thus we can't implement drop-handling
#[unstable(issue = "none", feature = "std_internals")]
impl<T: Copy> NonDrop for T {}
#[doc(hidden)]
#[unstable(issue = "none", feature = "std_internals")]
// TrustedRandomAccess (without NoCoerce) must not be implemented because
// subtypes/supertypes of `T` might not be `NonDrop`
unsafe impl<T, A: Allocator> TrustedRandomAccessNoCoerce for IntoIter<T, A>
where
T: NonDrop,
{
const MAY_HAVE_SIDE_EFFECT: bool = false;
}
#[cfg(not(no_global_oom_handling))]
#[stable(feature = "vec_into_iter_clone", since = "1.8.0")]
impl<T: Clone, A: Allocator + Clone> Clone for IntoIter<T, A> {
#[cfg(not(test))]
fn clone(&self) -> Self {
self.as_slice().to_vec_in(self.alloc.deref().clone()).into_iter()
}
#[cfg(test)]
fn clone(&self) -> Self {
crate::slice::to_vec(self.as_slice(), self.alloc.deref().clone()).into_iter()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
unsafe impl<#[may_dangle] T, A: Allocator> Drop for IntoIter<T, A> {
fn drop(&mut self) {
struct DropGuard<'a, T, A: Allocator>(&'a mut IntoIter<T, A>);
impl<T, A: Allocator> Drop for DropGuard<'_, T, A> {
fn drop(&mut self) {
unsafe {
// `IntoIter::alloc` is not used anymore after this and will be dropped by RawVec
let alloc = ManuallyDrop::take(&mut self.0.alloc);
// RawVec handles deallocation
let _ = RawVec::from_raw_parts_in(self.0.buf.as_ptr(), self.0.cap, alloc);
}
}
}
let guard = DropGuard(self);
// destroy the remaining elements
unsafe {
ptr::drop_in_place(guard.0.as_raw_mut_slice());
}
// now `guard` will be dropped and do the rest
}
}
// In addition to the SAFETY invariants of the following three unsafe traits
// also refer to the vec::in_place_collect module documentation to get an overview
#[unstable(issue = "none", feature = "inplace_iteration")]
#[doc(hidden)]
unsafe impl<T, A: Allocator> InPlaceIterable for IntoIter<T, A> {
const EXPAND_BY: Option<NonZeroUsize> = NonZeroUsize::new(1);
const MERGE_BY: Option<NonZeroUsize> = NonZeroUsize::new(1);
}
#[unstable(issue = "none", feature = "inplace_iteration")]
#[doc(hidden)]
unsafe impl<T, A: Allocator> SourceIter for IntoIter<T, A> {
type Source = Self;
#[inline]
unsafe fn as_inner(&mut self) -> &mut Self::Source {
self
}
}
#[cfg(not(no_global_oom_handling))]
unsafe impl<T> AsVecIntoIter for IntoIter<T> {
type Item = T;
fn as_into_iter(&mut self) -> &mut IntoIter<Self::Item> {
self
}
}
rust/alloc/vec/is_zero.rs deleted 100644 → 0
View file @ 84c7d76b
// SPDX-License-Identifier: Apache-2.0 OR MIT
use core::num::{Saturating, Wrapping};
use crate::boxed::Box;
#[rustc_specialization_trait]
pub(super) unsafe trait IsZero {
/// Whether this value's representation is all zeros,
/// or can be represented with all zeroes.
fn is_zero(&self) -> bool;
}
macro_rules! impl_is_zero {
($t:ty, $is_zero:expr) => {
unsafe impl IsZero for $t {
#[inline]
fn is_zero(&self) -> bool {
$is_zero(*self)
}
}
};
}
impl_is_zero!(i8, |x| x == 0); // It is needed to impl for arrays and tuples of i8.
impl_is_zero!(i16, |x| x == 0);
impl_is_zero!(i32, |x| x == 0);
impl_is_zero!(i64, |x| x == 0);
impl_is_zero!(i128, |x| x == 0);
impl_is_zero!(isize, |x| x == 0);
impl_is_zero!(u8, |x| x == 0); // It is needed to impl for arrays and tuples of u8.
impl_is_zero!(u16, |x| x == 0);
impl_is_zero!(u32, |x| x == 0);
impl_is_zero!(u64, |x| x == 0);
impl_is_zero!(u128, |x| x == 0);
impl_is_zero!(usize, |x| x == 0);
impl_is_zero!(bool, |x| x == false);
impl_is_zero!(char, |x| x == '\0');
impl_is_zero!(f32, |x: f32| x.to_bits() == 0);
impl_is_zero!(f64, |x: f64| x.to_bits() == 0);
unsafe impl<T> IsZero for *const T {
#[inline]
fn is_zero(&self) -> bool {
(*self).is_null()
}
}
unsafe impl<T> IsZero for *mut T {
#[inline]
fn is_zero(&self) -> bool {
(*self).is_null()
}
}
unsafe impl<T: IsZero, const N: usize> IsZero for [T; N] {
#[inline]
fn is_zero(&self) -> bool {
// Because this is generated as a runtime check, it's not obvious that
// it's worth doing if the array is really long. The threshold here
// is largely arbitrary, but was picked because as of 2022-07-01 LLVM
// fails to const-fold the check in `vec![[1; 32]; n]`
// See https://github.com/rust-lang/rust/pull/97581#issuecomment-1166628022
// Feel free to tweak if you have better evidence.
N <= 16 && self.iter().all(IsZero::is_zero)
}
}
// This is recursive macro.
macro_rules! impl_for_tuples {
// Stopper
() => {
// No use for implementing for empty tuple because it is ZST.
};
($first_arg:ident $(,$rest:ident)*) => {
unsafe impl <$first_arg: IsZero, $($rest: IsZero,)*> IsZero for ($first_arg, $($rest,)*){
#[inline]
fn is_zero(&self) -> bool{
// Destructure tuple to N references
// Rust allows to hide generic params by local variable names.
#[allow(non_snake_case)]
let ($first_arg, $($rest,)*) = self;
$first_arg.is_zero()
$( && $rest.is_zero() )*
}
}
impl_for_tuples!($($rest),*);
}
}
impl_for_tuples!(A, B, C, D, E, F, G, H);
// `Option<&T>` and `Option<Box<T>>` are guaranteed to represent `None` as null.
// For fat pointers, the bytes that would be the pointer metadata in the `Some`
// variant are padding in the `None` variant, so ignoring them and
// zero-initializing instead is ok.
// `Option<&mut T>` never implements `Clone`, so there's no need for an impl of
// `SpecFromElem`.
unsafe impl<T: ?Sized> IsZero for Option<&T> {
#[inline]
fn is_zero(&self) -> bool {
self.is_none()
}
}
unsafe impl<T: ?Sized> IsZero for Option<Box<T>> {
#[inline]
fn is_zero(&self) -> bool {
self.is_none()
}
}
// `Option<num::NonZeroU32>` and similar have a representation guarantee that
// they're the same size as the corresponding `u32` type, as well as a guarantee
// that transmuting between `NonZeroU32` and `Option<num::NonZeroU32>` works.
// While the documentation officially makes it UB to transmute from `None`,
// we're the standard library so we can make extra inferences, and we know that
// the only niche available to represent `None` is the one that's all zeros.
macro_rules! impl_is_zero_option_of_nonzero {
($($t:ident,)+) => {$(
unsafe impl IsZero for Option<core::num::$t> {
#[inline]
fn is_zero(&self) -> bool {
self.is_none()
}
}
)+};
}
impl_is_zero_option_of_nonzero!(
NonZeroU8,
NonZeroU16,
NonZeroU32,
NonZeroU64,
NonZeroU128,
NonZeroI8,
NonZeroI16,
NonZeroI32,
NonZeroI64,
NonZeroI128,
NonZeroUsize,
NonZeroIsize,
);
macro_rules! impl_is_zero_option_of_num {
($($t:ty,)+) => {$(
unsafe impl IsZero for Option<$t> {
#[inline]
fn is_zero(&self) -> bool {
const {
let none: Self = unsafe { core::mem::MaybeUninit::zeroed().assume_init() };
assert!(none.is_none());
}
self.is_none()
}
}
)+};
}
impl_is_zero_option_of_num!(u8, u16, u32, u64, u128, i8, i16, i32, i64, i128, usize, isize,);
unsafe impl<T: IsZero> IsZero for Wrapping<T> {
#[inline]
fn is_zero(&self) -> bool {
self.0.is_zero()
}
}
unsafe impl<T: IsZero> IsZero for Saturating<T> {
#[inline]
fn is_zero(&self) -> bool {
self.0.is_zero()
}
}
macro_rules! impl_for_optional_bool {
($($t:ty,)+) => {$(
unsafe impl IsZero for $t {
#[inline]
fn is_zero(&self) -> bool {
// SAFETY: This is *not* a stable layout guarantee, but
// inside `core` we're allowed to rely on the current rustc
// behaviour that options of bools will be one byte with
// no padding, so long as they're nested less than 254 deep.
let raw: u8 = unsafe { core::mem::transmute(*self) };
raw == 0
}
}
)+};
}
impl_for_optional_bool! {
Option<bool>,
Option<Option<bool>>,
Option<Option<Option<bool>>>,
// Could go further, but not worth the metadata overhead
}
rust/alloc/vec/mod.rs deleted 100644 → 0
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rust/alloc/vec/partial_eq.rs deleted 100644 → 0
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// SPDX-License-Identifier: Apache-2.0 OR MIT
use crate::alloc::Allocator;
#[cfg(not(no_global_oom_handling))]
use crate::borrow::Cow;
use super::Vec;
macro_rules! __impl_slice_eq1 {
([$($vars:tt)*] $lhs:ty, $rhs:ty $(where $ty:ty: $bound:ident)?, #[$stability:meta]) => {
#[$stability]
impl<T, U, $($vars)*> PartialEq<$rhs> for $lhs
where
T: PartialEq<U>,
$($ty: $bound)?
{
#[inline]
fn eq(&self, other: &$rhs) -> bool { self[..] == other[..] }
#[inline]
fn ne(&self, other: &$rhs) -> bool { self[..] != other[..] }
}
}
}
__impl_slice_eq1! { [A1: Allocator, A2: Allocator] Vec<T, A1>, Vec<U, A2>, #[stable(feature = "rust1", since = "1.0.0")] }
__impl_slice_eq1! { [A: Allocator] Vec<T, A>, &[U], #[stable(feature = "rust1", since = "1.0.0")] }
__impl_slice_eq1! { [A: Allocator] Vec<T, A>, &mut [U], #[stable(feature = "rust1", since = "1.0.0")] }
__impl_slice_eq1! { [A: Allocator] &[T], Vec<U, A>, #[stable(feature = "partialeq_vec_for_ref_slice", since = "1.46.0")] }
__impl_slice_eq1! { [A: Allocator] &mut [T], Vec<U, A>, #[stable(feature = "partialeq_vec_for_ref_slice", since = "1.46.0")] }
__impl_slice_eq1! { [A: Allocator] Vec<T, A>, [U], #[stable(feature = "partialeq_vec_for_slice", since = "1.48.0")] }
__impl_slice_eq1! { [A: Allocator] [T], Vec<U, A>, #[stable(feature = "partialeq_vec_for_slice", since = "1.48.0")] }
#[cfg(not(no_global_oom_handling))]
__impl_slice_eq1! { [A: Allocator] Cow<'_, [T]>, Vec<U, A> where T: Clone, #[stable(feature = "rust1", since = "1.0.0")] }
#[cfg(not(no_global_oom_handling))]
__impl_slice_eq1! { [] Cow<'_, [T]>, &[U] where T: Clone, #[stable(feature = "rust1", since = "1.0.0")] }
#[cfg(not(no_global_oom_handling))]
__impl_slice_eq1! { [] Cow<'_, [T]>, &mut [U] where T: Clone, #[stable(feature = "rust1", since = "1.0.0")] }
__impl_slice_eq1! { [A: Allocator, const N: usize] Vec<T, A>, [U; N], #[stable(feature = "rust1", since = "1.0.0")] }
__impl_slice_eq1! { [A: Allocator, const N: usize] Vec<T, A>, &[U; N], #[stable(feature = "rust1", since = "1.0.0")] }
// NOTE: some less important impls are omitted to reduce code bloat
// FIXME(Centril): Reconsider this?
//__impl_slice_eq1! { [const N: usize] Vec<A>, &mut [B; N], }
//__impl_slice_eq1! { [const N: usize] [A; N], Vec<B>, }
//__impl_slice_eq1! { [const N: usize] &[A; N], Vec<B>, }
//__impl_slice_eq1! { [const N: usize] &mut [A; N], Vec<B>, }
//__impl_slice_eq1! { [const N: usize] Cow<'a, [A]>, [B; N], }
//__impl_slice_eq1! { [const N: usize] Cow<'a, [A]>, &[B; N], }
//__impl_slice_eq1! { [const N: usize] Cow<'a, [A]>, &mut [B; N], }
rust/alloc/vec/set_len_on_drop.rs deleted 100644 → 0
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// SPDX-License-Identifier: Apache-2.0 OR MIT
// Set the length of the vec when the `SetLenOnDrop` value goes out of scope.
//
// The idea is: The length field in SetLenOnDrop is a local variable
// that the optimizer will see does not alias with any stores through the Vec's data
// pointer. This is a workaround for alias analysis issue #32155
pub(super) struct SetLenOnDrop<'a> {
len: &'a mut usize,
local_len: usize,
}
impl<'a> SetLenOnDrop<'a> {
#[inline]
pub(super) fn new(len: &'a mut usize) -> Self {
SetLenOnDrop { local_len: *len, len }
}
#[inline]
pub(super) fn increment_len(&mut self, increment: usize) {
self.local_len += increment;
}
#[inline]
pub(super) fn current_len(&self) -> usize {
self.local_len
}
}
impl Drop for SetLenOnDrop<'_> {
#[inline]
fn drop(&mut self) {
*self.len = self.local_len;
}
}
rust/alloc/vec/spec_extend.rs deleted 100644 → 0
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// SPDX-License-Identifier: Apache-2.0 OR MIT
use crate::alloc::Allocator;
use crate::collections::TryReserveError;
use core::iter::TrustedLen;
use core::slice::{self};
use super::{IntoIter, Vec};
// Specialization trait used for Vec::extend
#[cfg(not(no_global_oom_handling))]
pub(super) trait SpecExtend<T, I> {
fn spec_extend(&mut self, iter: I);
}
// Specialization trait used for Vec::try_extend
pub(super) trait TrySpecExtend<T, I> {
fn try_spec_extend(&mut self, iter: I) -> Result<(), TryReserveError>;
}
#[cfg(not(no_global_oom_handling))]
impl<T, I, A: Allocator> SpecExtend<T, I> for Vec<T, A>
where
I: Iterator<Item = T>,
{
default fn spec_extend(&mut self, iter: I) {
self.extend_desugared(iter)
}
}
impl<T, I, A: Allocator> TrySpecExtend<T, I> for Vec<T, A>
where
I: Iterator<Item = T>,
{
default fn try_spec_extend(&mut self, iter: I) -> Result<(), TryReserveError> {
self.try_extend_desugared(iter)
}
}
#[cfg(not(no_global_oom_handling))]
impl<T, I, A: Allocator> SpecExtend<T, I> for Vec<T, A>
where
I: TrustedLen<Item = T>,
{
default fn spec_extend(&mut self, iterator: I) {
self.extend_trusted(iterator)
}
}
impl<T, I, A: Allocator> TrySpecExtend<T, I> for Vec<T, A>
where
I: TrustedLen<Item = T>,
{
default fn try_spec_extend(&mut self, iterator: I) -> Result<(), TryReserveError> {
self.try_extend_trusted(iterator)
}
}
#[cfg(not(no_global_oom_handling))]
impl<T, A: Allocator> SpecExtend<T, IntoIter<T>> for Vec<T, A> {
fn spec_extend(&mut self, mut iterator: IntoIter<T>) {
unsafe {
self.append_elements(iterator.as_slice() as _);
}
iterator.forget_remaining_elements();
}
}
impl<T, A: Allocator> TrySpecExtend<T, IntoIter<T>> for Vec<T, A> {
fn try_spec_extend(&mut self, mut iterator: IntoIter<T>) -> Result<(), TryReserveError> {
unsafe {
self.try_append_elements(iterator.as_slice() as _)?;
}
iterator.forget_remaining_elements();
Ok(())
}
}
#[cfg(not(no_global_oom_handling))]
impl<'a, T: 'a, I, A: Allocator> SpecExtend<&'a T, I> for Vec<T, A>
where
I: Iterator<Item = &'a T>,
T: Clone,
{
default fn spec_extend(&mut self, iterator: I) {
self.spec_extend(iterator.cloned())
}
}
impl<'a, T: 'a, I, A: Allocator> TrySpecExtend<&'a T, I> for Vec<T, A>
where
I: Iterator<Item = &'a T>,
T: Clone,
{
default fn try_spec_extend(&mut self, iterator: I) -> Result<(), TryReserveError> {
self.try_spec_extend(iterator.cloned())
}
}
#[cfg(not(no_global_oom_handling))]
impl<'a, T: 'a, A: Allocator> SpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T, A>
where
T: Copy,
{
fn spec_extend(&mut self, iterator: slice::Iter<'a, T>) {
let slice = iterator.as_slice();
unsafe { self.append_elements(slice) };
}
}
impl<'a, T: 'a, A: Allocator> TrySpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T, A>
where
T: Copy,
{
fn try_spec_extend(&mut self, iterator: slice::Iter<'a, T>) -> Result<(), TryReserveError> {
let slice = iterator.as_slice();
unsafe { self.try_append_elements(slice) }
}
}
rust/bindings/bindings_helper.h
View file @ 8f5b5f78
......@@ -20,5 +20,8 @@
/* `bindgen` gets confused at certain things. */
const size_t RUST_CONST_HELPER_ARCH_SLAB_MINALIGN = ARCH_SLAB_MINALIGN;
const gfp_t RUST_CONST_HELPER_GFP_ATOMIC = GFP_ATOMIC;
const gfp_t RUST_CONST_HELPER_GFP_KERNEL = GFP_KERNEL;
const gfp_t RUST_CONST_HELPER_GFP_KERNEL_ACCOUNT = GFP_KERNEL_ACCOUNT;
const gfp_t RUST_CONST_HELPER_GFP_NOWAIT = GFP_NOWAIT;
const gfp_t RUST_CONST_HELPER___GFP_ZERO = __GFP_ZERO;
rust/helpers.c
View file @ 8f5b5f78
......@@ -4,7 +4,7 @@
* cannot be called either. This file explicitly creates functions ("helpers")
* that wrap those so that they can be called from Rust.
*
* Even though Rust kernel modules should never use directly the bindings, some
* Even though Rust kernel modules should never use the bindings directly, some
* of these helpers need to be exported because Rust generics and inlined
* functions may not get their code generated in the crate where they are
* defined. Other helpers, called from non-inline functions, may not be
......
rust/kernel/alloc.rs 0 → 100644
View file @ 8f5b5f78
// SPDX-License-Identifier: GPL-2.0
//! Extensions to the [`alloc`] crate.
#[cfg(not(test))]
#[cfg(not(testlib))]
mod allocator;
pub mod box_ext;
pub mod vec_ext;
/// Indicates an allocation error.
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub struct AllocError;
/// Flags to be used when allocating memory.
///
/// They can be combined with the operators `|`, `&`, and `!`.
///
/// Values can be used from the [`flags`] module.
#[derive(Clone, Copy)]
pub struct Flags(u32);
impl core::ops::BitOr for Flags {
type Output = Self;
fn bitor(self, rhs: Self) -> Self::Output {
Self(self.0 | rhs.0)
}
}
impl core::ops::BitAnd for Flags {
type Output = Self;
fn bitand(self, rhs: Self) -> Self::Output {
Self(self.0 & rhs.0)
}
}
impl core::ops::Not for Flags {
type Output = Self;
fn not(self) -> Self::Output {
Self(!self.0)
}
}
/// Allocation flags.
///
/// These are meant to be used in functions that can allocate memory.
pub mod flags {
use super::Flags;
/// Zeroes out the allocated memory.
///
/// This is normally or'd with other flags.
pub const __GFP_ZERO: Flags = Flags(bindings::__GFP_ZERO);
/// Users can not sleep and need the allocation to succeed.
///
/// A lower watermark is applied to allow access to "atomic reserves". The current
/// implementation doesn't support NMI and few other strict non-preemptive contexts (e.g.
/// raw_spin_lock). The same applies to [`GFP_NOWAIT`].
pub const GFP_ATOMIC: Flags = Flags(bindings::GFP_ATOMIC);
/// Typical for kernel-internal allocations. The caller requires ZONE_NORMAL or a lower zone
/// for direct access but can direct reclaim.
pub const GFP_KERNEL: Flags = Flags(bindings::GFP_KERNEL);
/// The same as [`GFP_KERNEL`], except the allocation is accounted to kmemcg.
pub const GFP_KERNEL_ACCOUNT: Flags = Flags(bindings::GFP_KERNEL_ACCOUNT);
/// Ror kernel allocations that should not stall for direct reclaim, start physical IO or
/// use any filesystem callback. It is very likely to fail to allocate memory, even for very
/// small allocations.
pub const GFP_NOWAIT: Flags = Flags(bindings::GFP_NOWAIT);
}
rust/kernel/allocator.rs → rust/kernel/alloc/allocator.rs
View file @ 8f5b5f78
......@@ -2,11 +2,10 @@
//! Allocator support.
use super::{flags::*, Flags};
use core::alloc::{GlobalAlloc, Layout};
use core::ptr;
use crate::bindings;
struct KernelAllocator;
/// Calls `krealloc` with a proper size to alloc a new object aligned to `new_layout`'s alignment.
......@@ -15,7 +14,7 @@
///
/// - `ptr` can be either null or a pointer which has been allocated by this allocator.
/// - `new_layout` must have a non-zero size.
unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gfp_t) -> *mut u8 {
pub(crate) unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: Flags) -> *mut u8 {
// Customized layouts from `Layout::from_size_align()` can have size < align, so pad first.
let layout = new_layout.pad_to_align();
......@@ -36,14 +35,14 @@ unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gf
// function safety requirement.
// - `size` is greater than 0 since it's either a `layout.size()` (which cannot be zero
// according to the function safety requirement) or a result from `next_power_of_two()`.
unsafe { bindings::krealloc(ptr as *const core::ffi::c_void, size, flags) as *mut u8 }
unsafe { bindings::krealloc(ptr as *const core::ffi::c_void, size, flags.0) as *mut u8 }
}
unsafe impl GlobalAlloc for KernelAllocator {
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
// SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
// requirement.
unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
unsafe { krealloc_aligned(ptr::null_mut(), layout, GFP_KERNEL) }
}
unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
......@@ -64,19 +63,13 @@ unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut
// requirement.
// - the size of `layout` is not zero because `new_size` is not zero by the function safety
// requirement.
unsafe { krealloc_aligned(ptr, layout, bindings::GFP_KERNEL) }
unsafe { krealloc_aligned(ptr, layout, GFP_KERNEL) }
}
unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
// SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
// requirement.
unsafe {
krealloc_aligned(
ptr::null_mut(),
layout,
bindings::GFP_KERNEL | bindings::__GFP_ZERO,
)
}
unsafe { krealloc_aligned(ptr::null_mut(), layout, GFP_KERNEL | __GFP_ZERO) }
}
}
......
rust/kernel/alloc/box_ext.rs 0 → 100644
View file @ 8f5b5f78
// SPDX-License-Identifier: GPL-2.0
//! Extensions to [`Box`] for fallible allocations.
use super::{AllocError, Flags};
use alloc::boxed::Box;
use core::mem::MaybeUninit;
/// Extensions to [`Box`].
pub trait BoxExt<T>: Sized {
/// Allocates a new box.
///
/// The allocation may fail, in which case an error is returned.
fn new(x: T, flags: Flags) -> Result<Self, AllocError>;
/// Allocates a new uninitialised box.
///
/// The allocation may fail, in which case an error is returned.
fn new_uninit(flags: Flags) -> Result<Box<MaybeUninit<T>>, AllocError>;
}
impl<T> BoxExt<T> for Box<T> {
fn new(x: T, flags: Flags) -> Result<Self, AllocError> {
let b = <Self as BoxExt<_>>::new_uninit(flags)?;
Ok(Box::write(b, x))
}
#[cfg(any(test, testlib))]
fn new_uninit(_flags: Flags) -> Result<Box<MaybeUninit<T>>, AllocError> {
Ok(Box::new_uninit())
}
#[cfg(not(any(test, testlib)))]
fn new_uninit(flags: Flags) -> Result<Box<MaybeUninit<T>>, AllocError> {
let ptr = if core::mem::size_of::<MaybeUninit<T>>() == 0 {
core::ptr::NonNull::<_>::dangling().as_ptr()
} else {
let layout = core::alloc::Layout::new::<MaybeUninit<T>>();
// SAFETY: Memory is being allocated (first arg is null). The only other source of
// safety issues is sleeping on atomic context, which is addressed by klint. Lastly,
// the type is not a SZT (checked above).
let ptr =
unsafe { super::allocator::krealloc_aligned(core::ptr::null_mut(), layout, flags) };
if ptr.is_null() {
return Err(AllocError);
}
ptr.cast::<MaybeUninit<T>>()
};
// SAFETY: For non-zero-sized types, we allocate above using the global allocator. For
// zero-sized types, we use `NonNull::dangling`.
Ok(unsafe { Box::from_raw(ptr) })
}
}
rust/kernel/alloc/vec_ext.rs 0 → 100644
View file @ 8f5b5f78
// SPDX-License-Identifier: GPL-2.0
//! Extensions to [`Vec`] for fallible allocations.
use super::{AllocError, Flags};
use alloc::vec::Vec;
use core::ptr;
/// Extensions to [`Vec`].
pub trait VecExt<T>: Sized {
/// Creates a new [`Vec`] instance with at least the given capacity.
///
/// # Examples
///
/// ```
/// let v = Vec::<u32>::with_capacity(20, GFP_KERNEL)?;
///
/// assert!(v.capacity() >= 20);
/// # Ok::<(), Error>(())
/// ```
fn with_capacity(capacity: usize, flags: Flags) -> Result<Self, AllocError>;
/// Appends an element to the back of the [`Vec`] instance.
///
/// # Examples
///
/// ```
/// let mut v = Vec::new();
/// v.push(1, GFP_KERNEL)?;
/// assert_eq!(&v, &[1]);
///
/// v.push(2, GFP_KERNEL)?;
/// assert_eq!(&v, &[1, 2]);
/// # Ok::<(), Error>(())
/// ```
fn push(&mut self, v: T, flags: Flags) -> Result<(), AllocError>;
/// Pushes clones of the elements of slice into the [`Vec`] instance.
///
/// # Examples
///
/// ```
/// let mut v = Vec::new();
/// v.push(1, GFP_KERNEL)?;
///
/// v.extend_from_slice(&[20, 30, 40], GFP_KERNEL)?;
/// assert_eq!(&v, &[1, 20, 30, 40]);
///
/// v.extend_from_slice(&[50, 60], GFP_KERNEL)?;
/// assert_eq!(&v, &[1, 20, 30, 40, 50, 60]);
/// # Ok::<(), Error>(())
/// ```
fn extend_from_slice(&mut self, other: &[T], flags: Flags) -> Result<(), AllocError>
where
T: Clone;
/// Ensures that the capacity exceeds the length by at least `additional` elements.
///
/// # Examples
///
/// ```
/// let mut v = Vec::new();
/// v.push(1, GFP_KERNEL)?;
///
/// v.reserve(10, GFP_KERNEL)?;
/// let cap = v.capacity();
/// assert!(cap >= 10);
///
/// v.reserve(10, GFP_KERNEL)?;
/// let new_cap = v.capacity();
/// assert_eq!(new_cap, cap);
///
/// # Ok::<(), Error>(())
/// ```
fn reserve(&mut self, additional: usize, flags: Flags) -> Result<(), AllocError>;
}
impl<T> VecExt<T> for Vec<T> {
fn with_capacity(capacity: usize, flags: Flags) -> Result<Self, AllocError> {
let mut v = Vec::new();
<Self as VecExt<_>>::reserve(&mut v, capacity, flags)?;
Ok(v)
}
fn push(&mut self, v: T, flags: Flags) -> Result<(), AllocError> {
<Self as VecExt<_>>::reserve(self, 1, flags)?;
let s = self.spare_capacity_mut();
s[0].write(v);
// SAFETY: We just initialised the first spare entry, so it is safe to increase the length
// by 1. We also know that the new length is <= capacity because of the previous call to
// `reserve` above.
unsafe { self.set_len(self.len() + 1) };
Ok(())
}
fn extend_from_slice(&mut self, other: &[T], flags: Flags) -> Result<(), AllocError>
where
T: Clone,
{
<Self as VecExt<_>>::reserve(self, other.len(), flags)?;
for (slot, item) in core::iter::zip(self.spare_capacity_mut(), other) {
slot.write(item.clone());
}
// SAFETY: We just initialised the `other.len()` spare entries, so it is safe to increase
// the length by the same amount. We also know that the new length is <= capacity because
// of the previous call to `reserve` above.
unsafe { self.set_len(self.len() + other.len()) };
Ok(())
}
#[cfg(any(test, testlib))]
fn reserve(&mut self, additional: usize, _flags: Flags) -> Result<(), AllocError> {
Vec::reserve(self, additional);
Ok(())
}
#[cfg(not(any(test, testlib)))]
fn reserve(&mut self, additional: usize, flags: Flags) -> Result<(), AllocError> {
let len = self.len();
let cap = self.capacity();
if cap - len >= additional {
return Ok(());
}
if core::mem::size_of::<T>() == 0 {
// The capacity is already `usize::MAX` for SZTs, we can't go higher.
return Err(AllocError);
}
// We know cap is <= `isize::MAX` because `Layout::array` fails if the resulting byte size
// is greater than `isize::MAX`. So the multiplication by two won't overflow.
let new_cap = core::cmp::max(cap * 2, len.checked_add(additional).ok_or(AllocError)?);
let layout = core::alloc::Layout::array::<T>(new_cap).map_err(|_| AllocError)?;
let (old_ptr, len, cap) = destructure(self);
// We need to make sure that `ptr` is either NULL or comes from a previous call to
// `krealloc_aligned`. A `Vec<T>`'s `ptr` value is not guaranteed to be NULL and might be
// dangling after being created with `Vec::new`. Instead, we can rely on `Vec<T>`'s capacity
// to be zero if no memory has been allocated yet.
let ptr = if cap == 0 { ptr::null_mut() } else { old_ptr };
// SAFETY: `ptr` is valid because it's either NULL or comes from a previous call to
// `krealloc_aligned`. We also verified that the type is not a ZST.
let new_ptr = unsafe { super::allocator::krealloc_aligned(ptr.cast(), layout, flags) };
if new_ptr.is_null() {
// SAFETY: We are just rebuilding the existing `Vec` with no changes.
unsafe { rebuild(self, old_ptr, len, cap) };
Err(AllocError)
} else {
// SAFETY: `ptr` has been reallocated with the layout for `new_cap` elements. New cap
// is greater than `cap`, so it continues to be >= `len`.
unsafe { rebuild(self, new_ptr.cast::<T>(), len, new_cap) };
Ok(())
}
}
}
#[cfg(not(any(test, testlib)))]
fn destructure<T>(v: &mut Vec<T>) -> (*mut T, usize, usize) {
let mut tmp = Vec::new();
core::mem::swap(&mut tmp, v);
let mut tmp = core::mem::ManuallyDrop::new(tmp);
let len = tmp.len();
let cap = tmp.capacity();
(tmp.as_mut_ptr(), len, cap)
}
/// Rebuilds a `Vec` from a pointer, length, and capacity.
///
/// # Safety
///
/// The same as [`Vec::from_raw_parts`].
#[cfg(not(any(test, testlib)))]
unsafe fn rebuild<T>(v: &mut Vec<T>, ptr: *mut T, len: usize, cap: usize) {
// SAFETY: The safety requirements from this function satisfy those of `from_raw_parts`.
let mut tmp = unsafe { Vec::from_raw_parts(ptr, len, cap) };
core::mem::swap(&mut tmp, v);
}
rust/kernel/error.rs
View file @ 8f5b5f78
......@@ -4,14 +4,10 @@
//!
//! C header: [`include/uapi/asm-generic/errno-base.h`](srctree/include/uapi/asm-generic/errno-base.h)
use crate::str::CStr;
use crate::{alloc::AllocError, str::CStr};
use alloc::{
alloc::{AllocError, LayoutError},
collections::TryReserveError,
};
use alloc::alloc::LayoutError;
use core::convert::From;
use core::fmt;
use core::num::TryFromIntError;
use core::str::Utf8Error;
......@@ -192,12 +188,6 @@ fn from(_: Utf8Error) -> Error {
}
}
impl From<TryReserveError> for Error {
fn from(_: TryReserveError) -> Error {
code::ENOMEM
}
}
impl From<LayoutError> for Error {
fn from(_: LayoutError) -> Error {
code::ENOMEM
......
rust/kernel/init.rs
View file @ 8f5b5f78
......@@ -68,7 +68,7 @@
//! # a <- new_mutex!(42, "Foo::a"),
//! # b: 24,
//! # });
//! let foo: Result<Pin<Box<Foo>>> = Box::pin_init(foo);
//! let foo: Result<Pin<Box<Foo>>> = Box::pin_init(foo, GFP_KERNEL);
//! ```
//!
//! For more information see the [`pin_init!`] macro.
......@@ -80,14 +80,15 @@
//!
//! ```rust
//! # use kernel::sync::{new_mutex, Arc, Mutex};
//! let mtx: Result<Arc<Mutex<usize>>> = Arc::pin_init(new_mutex!(42, "example::mtx"));
//! let mtx: Result<Arc<Mutex<usize>>> =
//! Arc::pin_init(new_mutex!(42, "example::mtx"), GFP_KERNEL);
//! ```
//!
//! To declare an init macro/function you just return an [`impl PinInit<T, E>`]:
//!
//! ```rust
//! # #![allow(clippy::disallowed_names)]
//! # use kernel::{sync::Mutex, prelude::*, new_mutex, init::PinInit, try_pin_init};
//! # use kernel::{sync::Mutex, new_mutex, init::PinInit, try_pin_init};
//! #[pin_data]
//! struct DriverData {
//! #[pin]
......@@ -99,7 +100,7 @@
//! fn new() -> impl PinInit<Self, Error> {
//! try_pin_init!(Self {
//! status <- new_mutex!(0, "DriverData::status"),
//! buffer: Box::init(kernel::init::zeroed())?,
//! buffer: Box::init(kernel::init::zeroed(), GFP_KERNEL)?,
//! })
//! }
//! }
......@@ -121,7 +122,7 @@
//!
//! ```rust
//! # #![allow(unreachable_pub, clippy::disallowed_names)]
//! use kernel::{prelude::*, init, types::Opaque};
//! use kernel::{init, types::Opaque};
//! use core::{ptr::addr_of_mut, marker::PhantomPinned, pin::Pin};
//! # mod bindings {
//! # #![allow(non_camel_case_types)]
......@@ -210,13 +211,13 @@
//! [`pin_init!`]: crate::pin_init!
use crate::{
alloc::{box_ext::BoxExt, AllocError, Flags},
error::{self, Error},
sync::UniqueArc,
types::{Opaque, ScopeGuard},
};
use alloc::boxed::Box;
use core::{
alloc::AllocError,
cell::UnsafeCell,
convert::Infallible,
marker::PhantomData,
......@@ -305,9 +306,9 @@ macro_rules! stack_pin_init {
///
/// stack_try_pin_init!(let foo: Result<Pin<&mut Foo>, AllocError> = pin_init!(Foo {
/// a <- new_mutex!(42),
/// b: Box::try_new(Bar {
/// b: Box::new(Bar {
/// x: 64,
/// })?,
/// }, GFP_KERNEL)?,
/// }));
/// let foo = foo.unwrap();
/// pr_info!("a: {}", &*foo.a.lock());
......@@ -331,9 +332,9 @@ macro_rules! stack_pin_init {
///
/// stack_try_pin_init!(let foo: Pin<&mut Foo> =? pin_init!(Foo {
/// a <- new_mutex!(42),
/// b: Box::try_new(Bar {
/// b: Box::new(Bar {
/// x: 64,
/// })?,
/// }, GFP_KERNEL)?,
/// }));
/// pr_info!("a: {}", &*foo.a.lock());
/// # Ok::<_, AllocError>(())
......@@ -390,7 +391,7 @@ macro_rules! stack_try_pin_init {
/// },
/// });
/// # initializer }
/// # Box::pin_init(demo()).unwrap();
/// # Box::pin_init(demo(), GFP_KERNEL).unwrap();
/// ```
///
/// Arbitrary Rust expressions can be used to set the value of a variable.
......@@ -412,7 +413,7 @@ macro_rules! stack_try_pin_init {
///
/// ```rust
/// # #![allow(clippy::disallowed_names)]
/// # use kernel::{init, pin_init, prelude::*, init::*};
/// # use kernel::{init, pin_init, init::*};
/// # use core::pin::Pin;
/// # #[pin_data]
/// # struct Foo {
......@@ -460,7 +461,7 @@ macro_rules! stack_try_pin_init {
/// # })
/// # }
/// # }
/// let foo = Box::pin_init(Foo::new());
/// let foo = Box::pin_init(Foo::new(), GFP_KERNEL);
/// ```
///
/// They can also easily embed it into their own `struct`s:
......@@ -600,7 +601,7 @@ macro_rules! pin_init {
/// impl BigBuf {
/// fn new() -> impl PinInit<Self, Error> {
/// try_pin_init!(Self {
/// big: Box::init(init::zeroed())?,
/// big: Box::init(init::zeroed(), GFP_KERNEL)?,
/// small: [0; 1024 * 1024],
/// ptr: core::ptr::null_mut(),
/// }? Error)
......@@ -701,7 +702,7 @@ macro_rules! init {
/// impl BigBuf {
/// fn new() -> impl Init<Self, Error> {
/// try_init!(Self {
/// big: Box::init(zeroed())?,
/// big: Box::init(zeroed(), GFP_KERNEL)?,
/// small: [0; 1024 * 1024],
/// }? Error)
/// }
......@@ -1013,7 +1014,7 @@ pub fn uninit<T, E>() -> impl Init<MaybeUninit<T>, E> {
///
/// ```rust
/// use kernel::{error::Error, init::init_array_from_fn};
/// let array: Box<[usize; 1_000]> = Box::init::<Error>(init_array_from_fn(|i| i)).unwrap();
/// let array: Box<[usize; 1_000]> = Box::init::<Error>(init_array_from_fn(|i| i), GFP_KERNEL).unwrap();
/// assert_eq!(array.len(), 1_000);
/// ```
pub fn init_array_from_fn<I, const N: usize, T, E>(
......@@ -1057,7 +1058,7 @@ pub fn init_array_from_fn<I, const N: usize, T, E>(
/// ```rust
/// use kernel::{sync::{Arc, Mutex}, init::pin_init_array_from_fn, new_mutex};
/// let array: Arc<[Mutex<usize>; 1_000]> =
/// Arc::pin_init(pin_init_array_from_fn(|i| new_mutex!(i))).unwrap();
/// Arc::pin_init(pin_init_array_from_fn(|i| new_mutex!(i)), GFP_KERNEL).unwrap();
/// assert_eq!(array.len(), 1_000);
/// ```
pub fn pin_init_array_from_fn<I, const N: usize, T, E>(
......@@ -1115,7 +1116,7 @@ pub trait InPlaceInit<T>: Sized {
/// type.
///
/// If `T: !Unpin` it will not be able to move afterwards.
fn try_pin_init<E>(init: impl PinInit<T, E>) -> Result<Pin<Self>, E>
fn try_pin_init<E>(init: impl PinInit<T, E>, flags: Flags) -> Result<Pin<Self>, E>
where
E: From<AllocError>;
......@@ -1123,7 +1124,7 @@ fn try_pin_init<E>(init: impl PinInit<T, E>) -> Result<Pin<Self>, E>
/// type.
///
/// If `T: !Unpin` it will not be able to move afterwards.
fn pin_init<E>(init: impl PinInit<T, E>) -> error::Result<Pin<Self>>
fn pin_init<E>(init: impl PinInit<T, E>, flags: Flags) -> error::Result<Pin<Self>>
where
Error: From<E>,
{
......@@ -1131,16 +1132,16 @@ fn pin_init<E>(init: impl PinInit<T, E>) -> error::Result<Pin<Self>>
let init = unsafe {
pin_init_from_closure(|slot| init.__pinned_init(slot).map_err(|e| Error::from(e)))
};
Self::try_pin_init(init)
Self::try_pin_init(init, flags)
}
/// Use the given initializer to in-place initialize a `T`.
fn try_init<E>(init: impl Init<T, E>) -> Result<Self, E>
fn try_init<E>(init: impl Init<T, E>, flags: Flags) -> Result<Self, E>
where
E: From<AllocError>;
/// Use the given initializer to in-place initialize a `T`.
fn init<E>(init: impl Init<T, E>) -> error::Result<Self>
fn init<E>(init: impl Init<T, E>, flags: Flags) -> error::Result<Self>
where
Error: From<E>,
{
......@@ -1148,17 +1149,17 @@ fn init<E>(init: impl Init<T, E>) -> error::Result<Self>
let init = unsafe {
init_from_closure(|slot| init.__pinned_init(slot).map_err(|e| Error::from(e)))
};
Self::try_init(init)
Self::try_init(init, flags)
}
}
impl<T> InPlaceInit<T> for Box<T> {
#[inline]
fn try_pin_init<E>(init: impl PinInit<T, E>) -> Result<Pin<Self>, E>
fn try_pin_init<E>(init: impl PinInit<T, E>, flags: Flags) -> Result<Pin<Self>, E>
where
E: From<AllocError>,
{
let mut this = Box::try_new_uninit()?;
let mut this = <Box<_> as BoxExt<_>>::new_uninit(flags)?;
let slot = this.as_mut_ptr();
// SAFETY: When init errors/panics, slot will get deallocated but not dropped,
// slot is valid and will not be moved, because we pin it later.
......@@ -1168,11 +1169,11 @@ fn try_pin_init<E>(init: impl PinInit<T, E>) -> Result<Pin<Self>, E>
}
#[inline]
fn try_init<E>(init: impl Init<T, E>) -> Result<Self, E>
fn try_init<E>(init: impl Init<T, E>, flags: Flags) -> Result<Self, E>
where
E: From<AllocError>,
{
let mut this = Box::try_new_uninit()?;
let mut this = <Box<_> as BoxExt<_>>::new_uninit(flags)?;
let slot = this.as_mut_ptr();
// SAFETY: When init errors/panics, slot will get deallocated but not dropped,
// slot is valid.
......@@ -1184,11 +1185,11 @@ fn try_init<E>(init: impl Init<T, E>) -> Result<Self, E>
impl<T> InPlaceInit<T> for UniqueArc<T> {
#[inline]
fn try_pin_init<E>(init: impl PinInit<T, E>) -> Result<Pin<Self>, E>
fn try_pin_init<E>(init: impl PinInit<T, E>, flags: Flags) -> Result<Pin<Self>, E>
where
E: From<AllocError>,
{
let mut this = UniqueArc::try_new_uninit()?;
let mut this = UniqueArc::new_uninit(flags)?;
let slot = this.as_mut_ptr();
// SAFETY: When init errors/panics, slot will get deallocated but not dropped,
// slot is valid and will not be moved, because we pin it later.
......@@ -1198,11 +1199,11 @@ fn try_pin_init<E>(init: impl PinInit<T, E>) -> Result<Pin<Self>, E>
}
#[inline]
fn try_init<E>(init: impl Init<T, E>) -> Result<Self, E>
fn try_init<E>(init: impl Init<T, E>, flags: Flags) -> Result<Self, E>
where
E: From<AllocError>,
{
let mut this = UniqueArc::try_new_uninit()?;
let mut this = UniqueArc::new_uninit(flags)?;
let slot = this.as_mut_ptr();
// SAFETY: When init errors/panics, slot will get deallocated but not dropped,
// slot is valid.
......
rust/kernel/init/macros.rs
View file @ 8f5b5f78
......@@ -250,7 +250,7 @@
//! // error type is `Infallible`) we will need to drop this field if there
//! // is an error later. This `DropGuard` will drop the field when it gets
//! // dropped and has not yet been forgotten.
//! let t = unsafe {
//! let __t_guard = unsafe {
//! ::pinned_init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).t))
//! };
//! // Expansion of `x: 0,`:
......@@ -261,14 +261,14 @@
//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).x), x) };
//! }
//! // We again create a `DropGuard`.
//! let x = unsafe {
//! let __x_guard = unsafe {
//! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).x))
//! };
//! // Since initialization has successfully completed, we can now forget
//! // the guards. This is not `mem::forget`, since we only have
//! // `&DropGuard`.
//! ::core::mem::forget(x);
//! ::core::mem::forget(t);
//! ::core::mem::forget(__x_guard);
//! ::core::mem::forget(__t_guard);
//! // Here we use the type checker to ensure that every field has been
//! // initialized exactly once, since this is `if false` it will never get
//! // executed, but still type-checked.
......@@ -461,16 +461,16 @@
//! {
//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).a), a) };
//! }
//! let a = unsafe {
//! let __a_guard = unsafe {
//! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).a))
//! };
//! let init = Bar::new(36);
//! unsafe { data.b(::core::addr_of_mut!((*slot).b), b)? };
//! let b = unsafe {
//! let __b_guard = unsafe {
//! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).b))
//! };
//! ::core::mem::forget(b);
//! ::core::mem::forget(a);
//! ::core::mem::forget(__b_guard);
//! ::core::mem::forget(__a_guard);
//! #[allow(unreachable_code, clippy::diverging_sub_expression)]
//! let _ = || {
//! unsafe {
......@@ -538,6 +538,7 @@ macro_rules! __pin_data {
),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
@decl_generics($($decl_generics:tt)*),
@body({ $($fields:tt)* }),
) => {
// We now use token munching to iterate through all of the fields. While doing this we
......@@ -560,6 +561,9 @@ macro_rules! __pin_data {
@impl_generics($($impl_generics)*),
// The 'ty generics', the generics that will need to be specified on the impl blocks.
@ty_generics($($ty_generics)*),
// The 'decl generics', the generics that need to be specified on the struct
// definition.
@decl_generics($($decl_generics)*),
// The where clause of any impl block and the declaration.
@where($($($whr)*)?),
// The remaining fields tokens that need to be processed.
......@@ -585,6 +589,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
@decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We found a PhantomPinned field, this should generally be pinned!
@fields_munch($field:ident : $($($(::)?core::)?marker::)?PhantomPinned, $($rest:tt)*),
......@@ -607,6 +612,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
@decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($($rest)*),
@pinned($($pinned)* $($accum)* $field: ::core::marker::PhantomPinned,),
......@@ -623,6 +629,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
@decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We reached the field declaration.
@fields_munch($field:ident : $type:ty, $($rest:tt)*),
......@@ -640,6 +647,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
@decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($($rest)*),
@pinned($($pinned)* $($accum)* $field: $type,),
......@@ -656,6 +664,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
@decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We reached the field declaration.
@fields_munch($field:ident : $type:ty, $($rest:tt)*),
......@@ -673,6 +682,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
@decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($($rest)*),
@pinned($($pinned)*),
......@@ -689,6 +699,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
@decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We found the `#[pin]` attr.
@fields_munch(#[pin] $($rest:tt)*),
......@@ -705,6 +716,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
@decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($($rest)*),
// We do not include `#[pin]` in the list of attributes, since it is not actually an
......@@ -724,6 +736,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
@decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We reached the field declaration with visibility, for simplicity we only munch the
// visibility and put it into `$accum`.
......@@ -741,6 +754,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
@decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($field $($rest)*),
@pinned($($pinned)*),
......@@ -757,6 +771,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
@decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// Some other attribute, just put it into `$accum`.
@fields_munch(#[$($attr:tt)*] $($rest:tt)*),
......@@ -773,6 +788,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
@decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($($rest)*),
@pinned($($pinned)*),
......@@ -789,6 +805,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
@decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We reached the end of the fields, plus an optional additional comma, since we added one
// before and the user is also allowed to put a trailing comma.
......@@ -802,7 +819,7 @@ macro_rules! __pin_data {
) => {
// Declare the struct with all fields in the correct order.
$($struct_attrs)*
$vis struct $name <$($impl_generics)*>
$vis struct $name <$($decl_generics)*>
where $($whr)*
{
$($fields)*
......@@ -1192,14 +1209,14 @@ fn assert_zeroable<T: $crate::init::Zeroable>(_: *mut T) {}
// We use `paste!` to create new hygiene for `$field`.
::kernel::macros::paste! {
// SAFETY: We forget the guard later when initialization has succeeded.
let [<$field>] = unsafe {
let [< __ $field _guard >] = unsafe {
$crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
};
$crate::__init_internal!(init_slot($use_data):
@data($data),
@slot($slot),
@guards([<$field>], $($guards,)*),
@guards([< __ $field _guard >], $($guards,)*),
@munch_fields($($rest)*),
);
}
......@@ -1223,14 +1240,14 @@ fn assert_zeroable<T: $crate::init::Zeroable>(_: *mut T) {}
// We use `paste!` to create new hygiene for `$field`.
::kernel::macros::paste! {
// SAFETY: We forget the guard later when initialization has succeeded.
let [<$field>] = unsafe {
let [< __ $field _guard >] = unsafe {
$crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
};
$crate::__init_internal!(init_slot():
@data($data),
@slot($slot),
@guards([<$field>], $($guards,)*),
@guards([< __ $field _guard >], $($guards,)*),
@munch_fields($($rest)*),
);
}
......@@ -1255,14 +1272,14 @@ fn assert_zeroable<T: $crate::init::Zeroable>(_: *mut T) {}
// We use `paste!` to create new hygiene for `$field`.
::kernel::macros::paste! {
// SAFETY: We forget the guard later when initialization has succeeded.
let [<$field>] = unsafe {
let [< __ $field _guard >] = unsafe {
$crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
};
$crate::__init_internal!(init_slot($($use_data)?):
@data($data),
@slot($slot),
@guards([<$field>], $($guards,)*),
@guards([< __ $field _guard >], $($guards,)*),
@munch_fields($($rest)*),
);
}
......
rust/kernel/lib.rs
View file @ 8f5b5f78
......@@ -12,11 +12,9 @@
//! do so first instead of bypassing this crate.
#![no_std]
#![feature(allocator_api)]
#![feature(coerce_unsized)]
#![feature(dispatch_from_dyn)]
#![feature(new_uninit)]
#![feature(offset_of)]
#![feature(receiver_trait)]
#![feature(unsize)]
......@@ -28,9 +26,7 @@
// Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate).
extern crate self as kernel;
#[cfg(not(test))]
#[cfg(not(testlib))]
mod allocator;
pub mod alloc;
mod build_assert;
pub mod error;
pub mod init;
......@@ -92,6 +88,13 @@ impl ThisModule {
pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
ThisModule(ptr)
}
/// Access the raw pointer for this module.
///
/// It is up to the user to use it correctly.
pub const fn as_ptr(&self) -> *mut bindings::module {
self.0
}
}
#[cfg(not(any(testlib, test)))]
......
rust/kernel/net/phy.rs
View file @ 8f5b5f78
......@@ -6,7 +6,7 @@
//!
//! C headers: [`include/linux/phy.h`](srctree/include/linux/phy.h).
use crate::{bindings, error::*, prelude::*, str::CStr, types::Opaque};
use crate::{error::*, prelude::*, types::Opaque};
use core::marker::PhantomData;
......
rust/kernel/prelude.rs
View file @ 8f5b5f78
......@@ -14,6 +14,8 @@
#[doc(no_inline)]
pub use core::pin::Pin;
pub use crate::alloc::{box_ext::BoxExt, flags::*, vec_ext::VecExt};
#[doc(no_inline)]
pub use alloc::{boxed::Box, vec::Vec};
......
rust/kernel/print.rs
View file @ 8f5b5f78
......@@ -13,9 +13,6 @@
use crate::str::RawFormatter;
#[cfg(CONFIG_PRINTK)]
use crate::bindings;
// Called from `vsprintf` with format specifier `%pA`.
#[no_mangle]
unsafe extern "C" fn rust_fmt_argument(
......@@ -35,8 +32,6 @@
/// Public but hidden since it should only be used from public macros.
#[doc(hidden)]
pub mod format_strings {
use crate::bindings;
/// The length we copy from the `KERN_*` kernel prefixes.
const LENGTH_PREFIX: usize = 2;
......
rust/kernel/std_vendor.rs
View file @ 8f5b5f78
......@@ -146,15 +146,16 @@ macro_rules! dbg {
// `$val` expression could be a block (`{ .. }`), in which case the `pr_info!`
// will be malformed.
() => {
$crate::pr_info!("[{}:{}]\n", ::core::file!(), ::core::line!())
$crate::pr_info!("[{}:{}:{}]\n", ::core::file!(), ::core::line!(), ::core::column!())
};
($val:expr $(,)?) => {
// Use of `match` here is intentional because it affects the lifetimes
// of temporaries - https://stackoverflow.com/a/48732525/1063961
match $val {
tmp => {
$crate::pr_info!("[{}:{}] {} = {:#?}\n",
::core::file!(), ::core::line!(), ::core::stringify!($val), &tmp);
$crate::pr_info!("[{}:{}:{}] {} = {:#?}\n",
::core::file!(), ::core::line!(), ::core::column!(),
::core::stringify!($val), &tmp);
tmp
}
}
......
rust/kernel/str.rs
View file @ 8f5b5f78
......@@ -2,15 +2,12 @@
//! String representations.
use alloc::alloc::AllocError;
use crate::alloc::{flags::*, vec_ext::VecExt, AllocError};
use alloc::vec::Vec;
use core::fmt::{self, Write};
use core::ops::{self, Deref, Index};
use core::ops::{self, Deref, DerefMut, Index};
use crate::{
bindings,
error::{code::*, Error},
};
use crate::error::{code::*, Error};
/// Byte string without UTF-8 validity guarantee.
#[repr(transparent)]
......@@ -236,6 +233,19 @@ pub const fn from_bytes_with_nul(bytes: &[u8]) -> Result<&Self, CStrConvertError
unsafe { core::mem::transmute(bytes) }
}
/// Creates a mutable [`CStr`] from a `[u8]` without performing any
/// additional checks.
///
/// # Safety
///
/// `bytes` *must* end with a `NUL` byte, and should only have a single
/// `NUL` byte (or the string will be truncated).
#[inline]
pub unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) -> &mut CStr {
// SAFETY: Properties of `bytes` guaranteed by the safety precondition.
unsafe { &mut *(bytes as *mut [u8] as *mut CStr) }
}
/// Returns a C pointer to the string.
#[inline]
pub const fn as_char_ptr(&self) -> *const core::ffi::c_char {
......@@ -299,6 +309,70 @@ pub unsafe fn as_str_unchecked(&self) -> &str {
pub fn to_cstring(&self) -> Result<CString, AllocError> {
CString::try_from(self)
}
/// Converts this [`CStr`] to its ASCII lower case equivalent in-place.
///
/// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z',
/// but non-ASCII letters are unchanged.
///
/// To return a new lowercased value without modifying the existing one, use
/// [`to_ascii_lowercase()`].
///
/// [`to_ascii_lowercase()`]: #method.to_ascii_lowercase
pub fn make_ascii_lowercase(&mut self) {
// INVARIANT: This doesn't introduce or remove NUL bytes in the C
// string.
self.0.make_ascii_lowercase();
}
/// Converts this [`CStr`] to its ASCII upper case equivalent in-place.
///
/// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
/// but non-ASCII letters are unchanged.
///
/// To return a new uppercased value without modifying the existing one, use
/// [`to_ascii_uppercase()`].
///
/// [`to_ascii_uppercase()`]: #method.to_ascii_uppercase
pub fn make_ascii_uppercase(&mut self) {
// INVARIANT: This doesn't introduce or remove NUL bytes in the C
// string.
self.0.make_ascii_uppercase();
}
/// Returns a copy of this [`CString`] where each character is mapped to its
/// ASCII lower case equivalent.
///
/// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z',
/// but non-ASCII letters are unchanged.
///
/// To lowercase the value in-place, use [`make_ascii_lowercase`].
///
/// [`make_ascii_lowercase`]: str::make_ascii_lowercase
pub fn to_ascii_lowercase(&self) -> Result<CString, AllocError> {
let mut s = self.to_cstring()?;
s.make_ascii_lowercase();
Ok(s)
}
/// Returns a copy of this [`CString`] where each character is mapped to its
/// ASCII upper case equivalent.
///
/// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
/// but non-ASCII letters are unchanged.
///
/// To uppercase the value in-place, use [`make_ascii_uppercase`].
///
/// [`make_ascii_uppercase`]: str::make_ascii_uppercase
pub fn to_ascii_uppercase(&self) -> Result<CString, AllocError> {
let mut s = self.to_cstring()?;
s.make_ascii_uppercase();
Ok(s)
}
}
impl fmt::Display for CStr {
......@@ -729,7 +803,7 @@ pub fn try_from_fmt(args: fmt::Arguments<'_>) -> Result<Self, Error> {
let size = f.bytes_written();
// Allocate a vector with the required number of bytes, and write to it.
let mut buf = Vec::try_with_capacity(size)?;
let mut buf = <Vec<_> as VecExt<_>>::with_capacity(size, GFP_KERNEL)?;
// SAFETY: The buffer stored in `buf` is at least of size `size` and is valid for writes.
let mut f = unsafe { Formatter::from_buffer(buf.as_mut_ptr(), size) };
f.write_fmt(args)?;
......@@ -764,13 +838,21 @@ fn deref(&self) -> &Self::Target {
}
}
impl DerefMut for CString {
fn deref_mut(&mut self) -> &mut Self::Target {
// SAFETY: A `CString` is always NUL-terminated and contains no other
// NUL bytes.
unsafe { CStr::from_bytes_with_nul_unchecked_mut(self.buf.as_mut_slice()) }
}
}
impl<'a> TryFrom<&'a CStr> for CString {
type Error = AllocError;
fn try_from(cstr: &'a CStr) -> Result<CString, AllocError> {
let mut buf = Vec::new();
buf.try_extend_from_slice(cstr.as_bytes_with_nul())
<Vec<_> as VecExt<_>>::extend_from_slice(&mut buf, cstr.as_bytes_with_nul(), GFP_KERNEL)
.map_err(|_| AllocError)?;
// INVARIANT: The `CStr` and `CString` types have the same invariants for
......
rust/kernel/sync.rs
View file @ 8f5b5f78
......@@ -37,6 +37,12 @@ pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key {
}
}
impl Default for LockClassKey {
fn default() -> Self {
Self::new()
}
}
/// Defines a new static lock class and returns a pointer to it.
#[doc(hidden)]
#[macro_export]
......
rust/kernel/sync/arc.rs
View file @ 8f5b5f78
......@@ -16,7 +16,7 @@
//! [`Arc`]: https://doc.rust-lang.org/std/sync/struct.Arc.html
use crate::{
bindings,
alloc::{box_ext::BoxExt, AllocError, Flags},
error::{self, Error},
init::{self, InPlaceInit, Init, PinInit},
try_init,
......@@ -24,7 +24,7 @@
};
use alloc::boxed::Box;
use core::{
alloc::{AllocError, Layout},
alloc::Layout,
fmt,
marker::{PhantomData, Unsize},
mem::{ManuallyDrop, MaybeUninit},
......@@ -57,7 +57,7 @@
/// }
///
/// // Create a refcounted instance of `Example`.
/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
/// let obj = Arc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
///
/// // Get a new pointer to `obj` and increment the refcount.
/// let cloned = obj.clone();
......@@ -96,7 +96,7 @@
/// }
/// }
///
/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
/// let obj = Arc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
/// obj.use_reference();
/// obj.take_over();
/// # Ok::<(), Error>(())
......@@ -119,7 +119,7 @@
/// impl MyTrait for Example {}
///
/// // `obj` has type `Arc<Example>`.
/// let obj: Arc<Example> = Arc::try_new(Example)?;
/// let obj: Arc<Example> = Arc::new(Example, GFP_KERNEL)?;
///
/// // `coerced` has type `Arc<dyn MyTrait>`.
/// let coerced: Arc<dyn MyTrait> = obj;
......@@ -137,6 +137,39 @@ struct ArcInner<T: ?Sized> {
data: T,
}
impl<T: ?Sized> ArcInner<T> {
/// Converts a pointer to the contents of an [`Arc`] into a pointer to the [`ArcInner`].
///
/// # Safety
///
/// `ptr` must have been returned by a previous call to [`Arc::into_raw`], and the `Arc` must
/// not yet have been destroyed.
unsafe fn container_of(ptr: *const T) -> NonNull<ArcInner<T>> {
let refcount_layout = Layout::new::<bindings::refcount_t>();
// SAFETY: The caller guarantees that the pointer is valid.
let val_layout = Layout::for_value(unsafe { &*ptr });
// SAFETY: We're computing the layout of a real struct that existed when compiling this
// binary, so its layout is not so large that it can trigger arithmetic overflow.
let val_offset = unsafe { refcount_layout.extend(val_layout).unwrap_unchecked().1 };
// Pointer casts leave the metadata unchanged. This is okay because the metadata of `T` and
// `ArcInner<T>` is the same since `ArcInner` is a struct with `T` as its last field.
//
// This is documented at:
// <https://doc.rust-lang.org/std/ptr/trait.Pointee.html>.
let ptr = ptr as *const ArcInner<T>;
// SAFETY: The pointer is in-bounds of an allocation both before and after offsetting the
// pointer, since it originates from a previous call to `Arc::into_raw` on an `Arc` that is
// still valid.
let ptr = unsafe { ptr.byte_sub(val_offset) };
// SAFETY: The pointer can't be null since you can't have an `ArcInner<T>` value at the null
// address.
unsafe { NonNull::new_unchecked(ptr.cast_mut()) }
}
}
// This is to allow [`Arc`] (and variants) to be used as the type of `self`.
impl<T: ?Sized> core::ops::Receiver for Arc<T> {}
......@@ -162,7 +195,7 @@ unsafe impl<T: ?Sized + Sync + Send> Sync for Arc<T> {}
impl<T> Arc<T> {
/// Constructs a new reference counted instance of `T`.
pub fn try_new(contents: T) -> Result<Self, AllocError> {
pub fn new(contents: T, flags: Flags) -> Result<Self, AllocError> {
// INVARIANT: The refcount is initialised to a non-zero value.
let value = ArcInner {
// SAFETY: There are no safety requirements for this FFI call.
......@@ -170,7 +203,7 @@ pub fn try_new(contents: T) -> Result<Self, AllocError> {
data: contents,
};
let inner = Box::try_new(value)?;
let inner = <Box<_> as BoxExt<_>>::new(value, flags)?;
// SAFETY: We just created `inner` with a reference count of 1, which is owned by the new
// `Arc` object.
......@@ -181,22 +214,22 @@ pub fn try_new(contents: T) -> Result<Self, AllocError> {
///
/// If `T: !Unpin` it will not be able to move afterwards.
#[inline]
pub fn pin_init<E>(init: impl PinInit<T, E>) -> error::Result<Self>
pub fn pin_init<E>(init: impl PinInit<T, E>, flags: Flags) -> error::Result<Self>
where
Error: From<E>,
{
UniqueArc::pin_init(init).map(|u| u.into())
UniqueArc::pin_init(init, flags).map(|u| u.into())
}
/// Use the given initializer to in-place initialize a `T`.
///
/// This is equivalent to [`Arc<T>::pin_init`], since an [`Arc`] is always pinned.
#[inline]
pub fn init<E>(init: impl Init<T, E>) -> error::Result<Self>
pub fn init<E>(init: impl Init<T, E>, flags: Flags) -> error::Result<Self>
where
Error: From<E>,
{
UniqueArc::init(init).map(|u| u.into())
UniqueArc::init(init, flags).map(|u| u.into())
}
}
......@@ -232,27 +265,13 @@ pub fn into_raw(self) -> *const T {
/// `ptr` must have been returned by a previous call to [`Arc::into_raw`]. Additionally, it
/// must not be called more than once for each previous call to [`Arc::into_raw`].
pub unsafe fn from_raw(ptr: *const T) -> Self {
let refcount_layout = Layout::new::<bindings::refcount_t>();
// SAFETY: The caller guarantees that the pointer is valid.
let val_layout = Layout::for_value(unsafe { &*ptr });
// SAFETY: We're computing the layout of a real struct that existed when compiling this
// binary, so its layout is not so large that it can trigger arithmetic overflow.
let val_offset = unsafe { refcount_layout.extend(val_layout).unwrap_unchecked().1 };
// Pointer casts leave the metadata unchanged. This is okay because the metadata of `T` and
// `ArcInner<T>` is the same since `ArcInner` is a struct with `T` as its last field.
//
// This is documented at:
// <https://doc.rust-lang.org/std/ptr/trait.Pointee.html>.
let ptr = ptr as *const ArcInner<T>;
// SAFETY: The pointer is in-bounds of an allocation both before and after offsetting the
// pointer, since it originates from a previous call to `Arc::into_raw` and is still valid.
let ptr = unsafe { ptr.byte_sub(val_offset) };
// SAFETY: The caller promises that this pointer originates from a call to `into_raw` on an
// `Arc` that is still valid.
let ptr = unsafe { ArcInner::container_of(ptr) };
// SAFETY: By the safety requirements we know that `ptr` came from `Arc::into_raw`, so the
// reference count held then will be owned by the new `Arc` object.
unsafe { Self::from_inner(NonNull::new_unchecked(ptr.cast_mut())) }
unsafe { Self::from_inner(ptr) }
}
/// Returns an [`ArcBorrow`] from the given [`Arc`].
......@@ -271,6 +290,68 @@ pub fn as_arc_borrow(&self) -> ArcBorrow<'_, T> {
pub fn ptr_eq(this: &Self, other: &Self) -> bool {
core::ptr::eq(this.ptr.as_ptr(), other.ptr.as_ptr())
}
/// Converts this [`Arc`] into a [`UniqueArc`], or destroys it if it is not unique.
///
/// When this destroys the `Arc`, it does so while properly avoiding races. This means that
/// this method will never call the destructor of the value.
///
/// # Examples
///
/// ```
/// use kernel::sync::{Arc, UniqueArc};
///
/// let arc = Arc::new(42, GFP_KERNEL)?;
/// let unique_arc = arc.into_unique_or_drop();
///
/// // The above conversion should succeed since refcount of `arc` is 1.
/// assert!(unique_arc.is_some());
///
/// assert_eq!(*(unique_arc.unwrap()), 42);
///
/// # Ok::<(), Error>(())
/// ```
///
/// ```
/// use kernel::sync::{Arc, UniqueArc};
///
/// let arc = Arc::new(42, GFP_KERNEL)?;
/// let another = arc.clone();
///
/// let unique_arc = arc.into_unique_or_drop();
///
/// // The above conversion should fail since refcount of `arc` is >1.
/// assert!(unique_arc.is_none());
///
/// # Ok::<(), Error>(())
/// ```
pub fn into_unique_or_drop(self) -> Option<Pin<UniqueArc<T>>> {
// We will manually manage the refcount in this method, so we disable the destructor.
let me = ManuallyDrop::new(self);
// SAFETY: We own a refcount, so the pointer is still valid.
let refcount = unsafe { me.ptr.as_ref() }.refcount.get();
// If the refcount reaches a non-zero value, then we have destroyed this `Arc` and will
// return without further touching the `Arc`. If the refcount reaches zero, then there are
// no other arcs, and we can create a `UniqueArc`.
//
// SAFETY: We own a refcount, so the pointer is not dangling.
let is_zero = unsafe { bindings::refcount_dec_and_test(refcount) };
if is_zero {
// SAFETY: We have exclusive access to the arc, so we can perform unsynchronized
// accesses to the refcount.
unsafe { core::ptr::write(refcount, bindings::REFCOUNT_INIT(1)) };
// INVARIANT: We own the only refcount to this arc, so we may create a `UniqueArc`. We
// must pin the `UniqueArc` because the values was previously in an `Arc`, and they pin
// their values.
Some(Pin::from(UniqueArc {
inner: ManuallyDrop::into_inner(me),
}))
} else {
None
}
}
}
impl<T: 'static> ForeignOwnable for Arc<T> {
......@@ -387,7 +468,7 @@ fn from(item: Pin<UniqueArc<T>>) -> Self {
/// e.into()
/// }
///
/// let obj = Arc::try_new(Example)?;
/// let obj = Arc::new(Example, GFP_KERNEL)?;
/// let cloned = do_something(obj.as_arc_borrow());
///
/// // Assert that both `obj` and `cloned` point to the same underlying object.
......@@ -411,7 +492,7 @@ fn from(item: Pin<UniqueArc<T>>) -> Self {
/// }
/// }
///
/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
/// let obj = Arc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
/// obj.as_arc_borrow().use_reference();
/// # Ok::<(), Error>(())
/// ```
......@@ -453,6 +534,27 @@ unsafe fn new(inner: NonNull<ArcInner<T>>) -> Self {
_p: PhantomData,
}
}
/// Creates an [`ArcBorrow`] to an [`Arc`] that has previously been deconstructed with
/// [`Arc::into_raw`].
///
/// # Safety
///
/// * The provided pointer must originate from a call to [`Arc::into_raw`].
/// * For the duration of the lifetime annotated on this `ArcBorrow`, the reference count must
/// not hit zero.
/// * For the duration of the lifetime annotated on this `ArcBorrow`, there must not be a
/// [`UniqueArc`] reference to this value.
pub unsafe fn from_raw(ptr: *const T) -> Self {
// SAFETY: The caller promises that this pointer originates from a call to `into_raw` on an
// `Arc` that is still valid.
let ptr = unsafe { ArcInner::container_of(ptr) };
// SAFETY: The caller promises that the value remains valid since the reference count must
// not hit zero, and no mutable reference will be created since that would involve a
// `UniqueArc`.
unsafe { Self::new(ptr) }
}
}
impl<T: ?Sized> From<ArcBorrow<'_, T>> for Arc<T> {
......@@ -499,7 +601,7 @@ fn deref(&self) -> &Self::Target {
/// }
///
/// fn test() -> Result<Arc<Example>> {
/// let mut x = UniqueArc::try_new(Example { a: 10, b: 20 })?;
/// let mut x = UniqueArc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?;
/// x.a += 1;
/// x.b += 1;
/// Ok(x.into())
......@@ -522,7 +624,7 @@ fn deref(&self) -> &Self::Target {
/// }
///
/// fn test() -> Result<Arc<Example>> {
/// let x = UniqueArc::try_new_uninit()?;
/// let x = UniqueArc::new_uninit(GFP_KERNEL)?;
/// Ok(x.write(Example { a: 10, b: 20 }).into())
/// }
///
......@@ -542,7 +644,7 @@ fn deref(&self) -> &Self::Target {
/// }
///
/// fn test() -> Result<Arc<Example>> {
/// let mut pinned = Pin::from(UniqueArc::try_new(Example { a: 10, b: 20 })?);
/// let mut pinned = Pin::from(UniqueArc::new(Example { a: 10, b: 20 }, GFP_KERNEL)?);
/// // We can modify `pinned` because it is `Unpin`.
/// pinned.as_mut().a += 1;
/// Ok(pinned.into())
......@@ -556,21 +658,24 @@ pub struct UniqueArc<T: ?Sized> {
impl<T> UniqueArc<T> {
/// Tries to allocate a new [`UniqueArc`] instance.
pub fn try_new(value: T) -> Result<Self, AllocError> {
pub fn new(value: T, flags: Flags) -> Result<Self, AllocError> {
Ok(Self {
// INVARIANT: The newly-created object has a refcount of 1.
inner: Arc::try_new(value)?,
inner: Arc::new(value, flags)?,
})
}
/// Tries to allocate a new [`UniqueArc`] instance whose contents are not initialised yet.
pub fn try_new_uninit() -> Result<UniqueArc<MaybeUninit<T>>, AllocError> {
pub fn new_uninit(flags: Flags) -> Result<UniqueArc<MaybeUninit<T>>, AllocError> {
// INVARIANT: The refcount is initialised to a non-zero value.
let inner = Box::try_init::<AllocError>(try_init!(ArcInner {
let inner = Box::try_init::<AllocError>(
try_init!(ArcInner {
// SAFETY: There are no safety requirements for this FFI call.
refcount: Opaque::new(unsafe { bindings::REFCOUNT_INIT(1) }),
data <- init::uninit::<T, AllocError>(),
}? AllocError))?;
}? AllocError),
flags,
)?;
Ok(UniqueArc {
// INVARIANT: The newly-created object has a refcount of 1.
// SAFETY: The pointer from the `Box` is valid.
......
rust/kernel/sync/condvar.rs
View file @ 8f5b5f78
......@@ -7,7 +7,6 @@
use super::{lock::Backend, lock::Guard, LockClassKey};
use crate::{
bindings,
init::PinInit,
pin_init,
str::CStr,
......@@ -75,7 +74,7 @@ macro_rules! new_condvar {
/// Box::pin_init(pin_init!(Example {
/// value <- new_mutex!(0),
/// value_changed <- new_condvar!(),
/// }))
/// }), GFP_KERNEL)
/// }
/// ```
///
......
rust/kernel/sync/lock.rs
View file @ 8f5b5f78
......@@ -6,7 +6,7 @@
//! spinlocks, raw spinlocks) to be provided with minimal effort.
use super::LockClassKey;
use crate::{bindings, init::PinInit, pin_init, str::CStr, types::Opaque, types::ScopeGuard};
use crate::{init::PinInit, pin_init, str::CStr, types::Opaque, types::ScopeGuard};
use core::{cell::UnsafeCell, marker::PhantomData, marker::PhantomPinned};
use macros::pin_data;
......
rust/kernel/sync/lock/mutex.rs
View file @ 8f5b5f78
......@@ -4,8 +4,6 @@
//!
//! This module allows Rust code to use the kernel's `struct mutex`.
use crate::bindings;
/// Creates a [`Mutex`] initialiser with the given name and a newly-created lock class.
///
/// It uses the name if one is given, otherwise it generates one based on the file name and line
......@@ -60,7 +58,7 @@ macro_rules! new_mutex {
/// }
///
/// // Allocate a boxed `Example`.
/// let e = Box::pin_init(Example::new())?;
/// let e = Box::pin_init(Example::new(), GFP_KERNEL)?;
/// assert_eq!(e.c, 10);
/// assert_eq!(e.d.lock().a, 20);
/// assert_eq!(e.d.lock().b, 30);
......
rust/kernel/sync/lock/spinlock.rs
View file @ 8f5b5f78
......@@ -4,8 +4,6 @@
//!
//! This module allows Rust code to use the kernel's `spinlock_t`.
use crate::bindings;
/// Creates a [`SpinLock`] initialiser with the given name and a newly-created lock class.
///
/// It uses the name if one is given, otherwise it generates one based on the file name and line
......@@ -58,7 +56,7 @@ macro_rules! new_spinlock {
/// }
///
/// // Allocate a boxed `Example`.
/// let e = Box::pin_init(Example::new())?;
/// let e = Box::pin_init(Example::new(), GFP_KERNEL)?;
/// assert_eq!(e.c, 10);
/// assert_eq!(e.d.lock().a, 20);
/// assert_eq!(e.d.lock().b, 30);
......
rust/kernel/task.rs
View file @ 8f5b5f78
......@@ -4,7 +4,7 @@
//!
//! C header: [`include/linux/sched.h`](srctree/include/linux/sched.h).
use crate::{bindings, types::Opaque};
use crate::types::Opaque;
use core::{
ffi::{c_int, c_long, c_uint},
marker::PhantomData,
......
rust/kernel/types.rs
View file @ 8f5b5f78
......@@ -157,11 +157,11 @@ unsafe fn from_foreign(_: *const core::ffi::c_void) -> Self {}
/// let mut vec =
/// ScopeGuard::new_with_data(Vec::new(), |v| pr_info!("vec had {} elements\n", v.len()));
///
/// vec.try_push(10u8)?;
/// vec.push(10u8, GFP_KERNEL)?;
/// if arg {
/// return Ok(());
/// }
/// vec.try_push(20u8)?;
/// vec.push(20u8, GFP_KERNEL)?;
/// Ok(())
/// }
///
......@@ -270,7 +270,7 @@ pub fn ffi_init(init_func: impl FnOnce(*mut T)) -> impl PinInit<Self> {
}
/// Returns a raw pointer to the opaque data.
pub fn get(&self) -> *mut T {
pub const fn get(&self) -> *mut T {
UnsafeCell::get(&self.value).cast::<T>()
}
......
rust/kernel/workqueue.rs
View file @ 8f5b5f78
......@@ -33,7 +33,6 @@
//! we do not need to specify ids for the fields.
//!
//! ```
//! use kernel::prelude::*;
//! use kernel::sync::Arc;
//! use kernel::workqueue::{self, impl_has_work, new_work, Work, WorkItem};
//!
......@@ -53,7 +52,7 @@
//! Arc::pin_init(pin_init!(MyStruct {
//! value,
//! work <- new_work!("MyStruct::work"),
//! }))
//! }), GFP_KERNEL)
//! }
//! }
//!
......@@ -75,7 +74,6 @@
//! The following example shows how multiple `work_struct` fields can be used:
//!
//! ```
//! use kernel::prelude::*;
//! use kernel::sync::Arc;
//! use kernel::workqueue::{self, impl_has_work, new_work, Work, WorkItem};
//!
......@@ -101,7 +99,7 @@
//! value_2,
//! work_1 <- new_work!("MyStruct::work_1"),
//! work_2 <- new_work!("MyStruct::work_2"),
//! }))
//! }), GFP_KERNEL)
//! }
//! }
//!
......@@ -132,11 +130,9 @@
//!
//! C header: [`include/linux/workqueue.h`](srctree/include/linux/workqueue.h)
use crate::{bindings, prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
use alloc::alloc::AllocError;
use alloc::boxed::Box;
use crate::alloc::{AllocError, Flags};
use crate::{prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
use core::marker::PhantomData;
use core::pin::Pin;
/// Creates a [`Work`] initialiser with the given name and a newly-created lock class.
#[macro_export]
......@@ -210,13 +206,17 @@ pub fn enqueue<W, const ID: u64>(&self, w: W) -> W::EnqueueOutput
/// Tries to spawn the given function or closure as a work item.
///
/// This method can fail because it allocates memory to store the work item.
pub fn try_spawn<T: 'static + Send + FnOnce()>(&self, func: T) -> Result<(), AllocError> {
pub fn try_spawn<T: 'static + Send + FnOnce()>(
&self,
flags: Flags,
func: T,
) -> Result<(), AllocError> {
let init = pin_init!(ClosureWork {
work <- new_work!("Queue::try_spawn"),
func: Some(func),
});
self.enqueue(Box::pin_init(init).map_err(|_| AllocError)?);
self.enqueue(Box::pin_init(init, flags).map_err(|_| AllocError)?);
Ok(())
}
}
......@@ -346,8 +346,10 @@ pub trait WorkItem<const ID: u64 = 0> {
/// This is a helper type used to associate a `work_struct` with the [`WorkItem`] that uses it.
///
/// [`run`]: WorkItemPointer::run
#[pin_data]
#[repr(transparent)]
pub struct Work<T: ?Sized, const ID: u64 = 0> {
#[pin]
work: Opaque<bindings::work_struct>,
_inner: PhantomData<T>,
}
......@@ -369,21 +371,22 @@ pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self
where
T: WorkItem<ID>,
{
// SAFETY: The `WorkItemPointer` implementation promises that `run` can be used as the work
// item function.
pin_init!(Self {
work <- Opaque::ffi_init(|slot| {
// SAFETY: The `WorkItemPointer` implementation promises that `run` can be used as
// the work item function.
unsafe {
kernel::init::pin_init_from_closure(move |slot| {
let slot = Self::raw_get(slot);
bindings::init_work_with_key(
slot,
Some(T::Pointer::run),
false,
name.as_char_ptr(),
key.as_ptr(),
);
Ok(())
})
)
}
}),
_inner: PhantomData,
})
}
/// Get a pointer to the inner `work_struct`.
......@@ -408,7 +411,6 @@ pub unsafe fn raw_get(ptr: *const Self) -> *mut bindings::work_struct {
/// like this:
///
/// ```no_run
/// use kernel::prelude::*;
/// use kernel::workqueue::{impl_has_work, Work};
///
/// struct MyWorkItem {
......
rust/macros/helpers.rs
View file @ 8f5b5f78
// SPDX-License-Identifier: GPL-2.0
use proc_macro::{token_stream, Group, Punct, Spacing, TokenStream, TokenTree};
use proc_macro::{token_stream, Group, TokenStream, TokenTree};
pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
if let Some(TokenTree::Ident(ident)) = it.next() {
......@@ -70,8 +70,40 @@ pub(crate) fn expect_end(it: &mut token_stream::IntoIter) {
}
}
/// Parsed generics.
///
/// See the field documentation for an explanation what each of the fields represents.
///
/// # Examples
///
/// ```rust,ignore
/// # let input = todo!();
/// let (Generics { decl_generics, impl_generics, ty_generics }, rest) = parse_generics(input);
/// quote! {
/// struct Foo<$($decl_generics)*> {
/// // ...
/// }
///
/// impl<$impl_generics> Foo<$ty_generics> {
/// fn foo() {
/// // ...
/// }
/// }
/// }
/// ```
pub(crate) struct Generics {
/// The generics with bounds and default values (e.g. `T: Clone, const N: usize = 0`).
///
/// Use this on type definitions e.g. `struct Foo<$decl_generics> ...` (or `union`/`enum`).
pub(crate) decl_generics: Vec<TokenTree>,
/// The generics with bounds (e.g. `T: Clone, const N: usize`).
///
/// Use this on `impl` blocks e.g. `impl<$impl_generics> Trait for ...`.
pub(crate) impl_generics: Vec<TokenTree>,
/// The generics without bounds and without default values (e.g. `T, N`).
///
/// Use this when you use the type that is declared with these generics e.g.
/// `Foo<$ty_generics>`.
pub(crate) ty_generics: Vec<TokenTree>,
}
......@@ -79,6 +111,8 @@ pub(crate) struct Generics {
///
/// The generics are not present in the rest, but a where clause might remain.
pub(crate) fn parse_generics(input: TokenStream) -> (Generics, Vec<TokenTree>) {
// The generics with bounds and default values.
let mut decl_generics = vec![];
// `impl_generics`, the declared generics with their bounds.
let mut impl_generics = vec![];
// Only the names of the generics, without any bounds.
......@@ -90,10 +124,17 @@ pub(crate) fn parse_generics(input: TokenStream) -> (Generics, Vec<TokenTree>) {
let mut toks = input.into_iter();
// If we are at the beginning of a generic parameter.
let mut at_start = true;
for tt in &mut toks {
let mut skip_until_comma = false;
while let Some(tt) = toks.next() {
if nesting == 1 && matches!(&tt, TokenTree::Punct(p) if p.as_char() == '>') {
// Found the end of the generics.
break;
} else if nesting >= 1 {
decl_generics.push(tt.clone());
}
match tt.clone() {
TokenTree::Punct(p) if p.as_char() == '<' => {
if nesting >= 1 {
if nesting >= 1 && !skip_until_comma {
// This is inside of the generics and part of some bound.
impl_generics.push(tt);
}
......@@ -105,49 +146,70 @@ pub(crate) fn parse_generics(input: TokenStream) -> (Generics, Vec<TokenTree>) {
break;
} else {
nesting -= 1;
if nesting >= 1 {
if nesting >= 1 && !skip_until_comma {
// We are still inside of the generics and part of some bound.
impl_generics.push(tt);
}
if nesting == 0 {
break;
}
}
}
tt => {
TokenTree::Punct(p) if skip_until_comma && p.as_char() == ',' => {
if nesting == 1 {
impl_generics.push(tt.clone());
impl_generics.push(tt);
skip_until_comma = false;
}
}
_ if !skip_until_comma => {
match nesting {
// If we haven't entered the generics yet, we still want to keep these tokens.
0 => rest.push(tt),
1 => {
// Here depending on the token, it might be a generic variable name.
match &tt {
// Ignore const.
TokenTree::Ident(i) if i.to_string() == "const" => {}
match tt.clone() {
TokenTree::Ident(i) if at_start && i.to_string() == "const" => {
let Some(name) = toks.next() else {
// Parsing error.
break;
};
impl_generics.push(tt);
impl_generics.push(name.clone());
ty_generics.push(name.clone());
decl_generics.push(name);
at_start = false;
}
TokenTree::Ident(_) if at_start => {
ty_generics.push(tt.clone());
// We also already push the `,` token, this makes it easier to append
// generics.
ty_generics.push(TokenTree::Punct(Punct::new(',', Spacing::Alone)));
impl_generics.push(tt.clone());
ty_generics.push(tt);
at_start = false;
}
TokenTree::Punct(p) if p.as_char() == ',' => at_start = true,
TokenTree::Punct(p) if p.as_char() == ',' => {
impl_generics.push(tt.clone());
ty_generics.push(tt);
at_start = true;
}
// Lifetimes begin with `'`.
TokenTree::Punct(p) if p.as_char() == '\'' && at_start => {
ty_generics.push(tt.clone());
impl_generics.push(tt.clone());
ty_generics.push(tt);
}
_ => {}
// Generics can have default values, we skip these.
TokenTree::Punct(p) if p.as_char() == '=' => {
skip_until_comma = true;
}
_ => impl_generics.push(tt),
}
if nesting >= 1 {
impl_generics.push(tt);
} else if nesting == 0 {
// If we haven't entered the generics yet, we still want to keep these tokens.
rest.push(tt);
}
_ => impl_generics.push(tt),
}
}
_ => {}
}
}
rest.extend(toks);
(
Generics {
impl_generics,
decl_generics,
ty_generics,
},
rest,
......
rust/macros/pin_data.rs
View file @ 8f5b5f78
......@@ -10,6 +10,7 @@ pub(crate) fn pin_data(args: TokenStream, input: TokenStream) -> TokenStream {
let (
Generics {
impl_generics,
decl_generics,
ty_generics,
},
rest,
......@@ -76,6 +77,7 @@ pub(crate) fn pin_data(args: TokenStream, input: TokenStream) -> TokenStream {
@sig(#(#rest)*),
@impl_generics(#(#impl_generics)*),
@ty_generics(#(#ty_generics)*),
@decl_generics(#(#decl_generics)*),
@body(#last),
});
quoted.extend(errs);
......
rust/macros/zeroable.rs
View file @ 8f5b5f78
......@@ -7,6 +7,7 @@ pub(crate) fn derive(input: TokenStream) -> TokenStream {
let (
Generics {
impl_generics,
decl_generics: _,
ty_generics,
},
mut rest,
......
samples/rust/rust_minimal.rs
View file @ 8f5b5f78
......@@ -22,9 +22,9 @@ fn init(_module: &'static ThisModule) -> Result<Self> {
pr_info!("Am I built-in? {}\n", !cfg!(MODULE));
let mut numbers = Vec::new();
numbers.try_push(72)?;
numbers.try_push(108)?;
numbers.try_push(200)?;
numbers.push(72, GFP_KERNEL)?;
numbers.push(108, GFP_KERNEL)?;
numbers.push(200, GFP_KERNEL)?;
Ok(RustMinimal { numbers })
}
......
samples/rust/rust_print.rs
View file @ 8f5b5f78
......@@ -18,8 +18,8 @@
fn arc_print() -> Result {
use kernel::sync::*;
let a = Arc::try_new(1)?;
let b = UniqueArc::try_new("hello, world")?;
let a = Arc::new(1, GFP_KERNEL)?;
let b = UniqueArc::new("hello, world", GFP_KERNEL)?;
// Prints the value of data in `a`.
pr_info!("{}", a);
......
scripts/Makefile.build
View file @ 8f5b5f78
......@@ -263,7 +263,7 @@ $(obj)/%.lst: $(src)/%.c FORCE
# Compile Rust sources (.rs)
# ---------------------------------------------------------------------------
rust_allowed_features := new_uninit,offset_of
rust_allowed_features := new_uninit
# `--out-dir` is required to avoid temporaries being created by `rustc` in the
# current working directory, which may be not accessible in the out-of-tree
......
scripts/Makefile.debug
View file @ 8f5b5f78
......@@ -17,6 +17,12 @@ endif
DEBUG_CFLAGS += $(debug-flags-y)
KBUILD_AFLAGS += $(debug-flags-y)
ifdef CONFIG_DEBUG_INFO_DWARF4
DEBUG_RUSTFLAGS += -Zdwarf-version=4
else ifdef CONFIG_DEBUG_INFO_DWARF5
DEBUG_RUSTFLAGS += -Zdwarf-version=5
endif
ifdef CONFIG_DEBUG_INFO_REDUCED
DEBUG_CFLAGS += -fno-var-tracking
DEBUG_RUSTFLAGS += -Cdebuginfo=1
......@@ -29,10 +35,12 @@ endif
ifdef CONFIG_DEBUG_INFO_COMPRESSED_ZLIB
DEBUG_CFLAGS += -gz=zlib
DEBUG_RUSTFLAGS += -Zdebuginfo-compression=zlib
KBUILD_AFLAGS += -gz=zlib
KBUILD_LDFLAGS += --compress-debug-sections=zlib
else ifdef CONFIG_DEBUG_INFO_COMPRESSED_ZSTD
DEBUG_CFLAGS += -gz=zstd
DEBUG_RUSTFLAGS += -Zdebuginfo-compression=zstd
KBUILD_AFLAGS += -gz=zstd
KBUILD_LDFLAGS += --compress-debug-sections=zstd
endif
......
scripts/generate_rust_analyzer.py
View file @ 8f5b5f78
......@@ -66,7 +66,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs):
append_crate(
"alloc",
srctree / "rust" / "alloc" / "lib.rs",
sysroot_src / "alloc" / "src" / "lib.rs",
["core", "compiler_builtins"],
cfg=crates_cfgs.get("alloc", []),
)
......
scripts/generate_rust_target.rs
View file @ 8f5b5f78
......@@ -154,7 +154,7 @@ fn main() {
ts.push("arch", "x86_64");
ts.push(
"data-layout",
"e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128",
"e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128",
);
let mut features = "-3dnow,-3dnowa,-mmx,+soft-float".to_string();
if cfg.has("MITIGATION_RETPOLINE") {
......
scripts/min-tool-version.sh
View file @ 8f5b5f78
......@@ -33,7 +33,7 @@ llvm)
fi
;;
rustc)
echo 1.76.0
echo 1.78.0
;;
bindgen)
echo 0.65.1
......
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